Programs & Examples On #Embedded control

pycharm running way slow

Every performance problem with PyCharm is unique, a solution that helps to one person will not work for another. The only proper way to fix your specific performance problem is by capturing the CPU profiler snapshot as described in this document and sending it to PyCharm support team, either by submitting a ticket or directly into the issue tracker.

After the CPU snapshot is analyzed, PyCharm team will work on a fix and release a new version which will (hopefully) not be affected by this specific performance problem. The team may also suggest you some configuration change or workaround to remedy the problem based on the analysis of the provided data.

All the other "solutions" (like enabling Power Save mode and changing the highlighting level) will just hide the real problems that should be fixed.

What are the differences in die() and exit() in PHP?

Functionally, they are identical. So to choose which one to use is totally a personal preference. Semantically in English, they are different. Die sounds negative. When I have a function which returns JSON data to the client and terminate the program, it can be awful if I call this function jsonDie(), and it is more appropriate to call it jsonExit(). For that reason, I always use exit instead of die.

How to call a Parent Class's method from Child Class in Python?

Python 3 has a different and simpler syntax for calling parent method.

If Foo class inherits from Bar, then from Bar.__init__ can be invoked from Foo via super().__init__():

class Foo(Bar):

    def __init__(self, *args, **kwargs):
        # invoke Bar.__init__
        super().__init__(*args, **kwargs)

SQL Server String Concatenation with Null

Use COALESCE. Instead of your_column use COALESCE(your_column, ''). This will return the empty string instead of NULL.

Windows equivalent of 'touch' (i.e. the node.js way to create an index.html)

If you have Cygwin installed in your PC, you can simply use the supplied executable for touch (also via windows command prompt):

C:\cygwin64\bin\touch.exe <file_path>

How to show empty data message in Datatables

I was finding same but lastly i found an answer. I hope this answer help you so much.

when your array is empty then you can send empty array just like

if(!empty($result))
        {
            echo json_encode($result);
        }
        else
        {
            echo json_encode(array('data'=>''));
        }

Thank you

Show Current Location and Nearby Places and Route between two places using Google Maps API in Android

  1. First go through this tutorial for getting familiar with Android Google Maps and this for API 2.

  2. To retrive the current location of device see this answer or this another answer and for API 2

  3. Then you can get places near by your location using Google Place API and for use of Place Api see this blog.

  4. After getting Placemarks of near by location use this blog with source code to show markers on map with balloon overlay with API 2.

  5. You also have great sample to draw route between two points on map look here in these links Link1 and Link2 and this Great Answer.

After following these steps you will be easily able to do your application. The only condition is, you will have to read it and understand it, because like magic its not going to be complete in a click.

What is a quick way to force CRLF in C# / .NET?

It depends on exactly what the requirements are. In particular, how do you want to handle "\r" on its own? Should that count as a line break or not? As an example, how should "a\n\rb" be treated? Is that one very odd line break, one "\n" break and then a rogue "\r", or two separate linebreaks? If "\r" and "\n" can both be linebreaks on their own, why should "\r\n" not be treated as two linebreaks?

Here's some code which I suspect is reasonably efficient.

using System;
using System.Text;

class LineBreaks
{    
    static void Main()
    {
        Test("a\nb");
        Test("a\nb\r\nc");
        Test("a\r\nb\r\nc");
        Test("a\rb\nc");
        Test("a\r");
        Test("a\n");
        Test("a\r\n");
    }

    static void Test(string input)
    {
        string normalized = NormalizeLineBreaks(input);
        string debug = normalized.Replace("\r", "\\r")
                                 .Replace("\n", "\\n");
        Console.WriteLine(debug);
    }

    static string NormalizeLineBreaks(string input)
    {
        // Allow 10% as a rough guess of how much the string may grow.
        // If we're wrong we'll either waste space or have extra copies -
        // it will still work
        StringBuilder builder = new StringBuilder((int) (input.Length * 1.1));

        bool lastWasCR = false;

        foreach (char c in input)
        {
            if (lastWasCR)
            {
                lastWasCR = false;
                if (c == '\n')
                {
                    continue; // Already written \r\n
                }
            }
            switch (c)
            {
                case '\r':
                    builder.Append("\r\n");
                    lastWasCR = true;
                    break;
                case '\n':
                    builder.Append("\r\n");
                    break;
                default:
                    builder.Append(c);
                    break;
            }
        }
        return builder.ToString();
    }
}

How to check if an array value exists?

You can test whether an array has a certain element at all or not with isset() or sometimes even better array_key_exists() (the documentation explains the differences). If you can't be sure if the array has an element with the index 'say' you should test that first or you might get 'warning: undefined index....' messages.

As for the test whether the element's value is equal to a string you can use == or (again sometimes better) the identity operator === which doesn't allow type juggling.

if( isset($something['say']) && 'bla'===$something['say'] ) {
  // ...
}

Returning multiple objects in an R function

You can also use super-assignment.

Rather than "<-" type "<<-". The function will recursively and repeatedly search one functional level higher for an object of that name. If it can't find one, it will create one on the global level.

Dockerfile copy keep subdirectory structure

If you want to copy a source directory entirely with the same directory structure, Then don't use a star(*). Write COPY command in Dockerfile as below.

COPY . destinatio-directory/ 

add/remove active class for ul list with jquery?

I used this:

$('.nav-list li.active').removeClass('active');
$(this).parent().addClass('active');

Since the active class is in the <li> element and what is clicked is the <a> element, the first line removes .active from all <li> and the second one (again, $(this) represents <a> which is the clicked element) adds .active to the direct parent, which is <li>.

Should I use != or <> for not equal in T-SQL?

I understand that the C syntax != is in SQL Server due to its Unix heritage (back in the Sybase SQL Server days, pre Microsoft SQL Server 6.5).

Pair/tuple data type in Go

You can do this. It looks more wordy than a tuple, but it's a big improvement because you get type checking.

Edit: Replaced snippet with complete working example, following Nick's suggestion. Playground link: http://play.golang.org/p/RNx_otTFpk

package main

import "fmt"

func main() {
    queue := make(chan struct {string; int})
    go sendPair(queue)
    pair := <-queue
    fmt.Println(pair.string, pair.int)
}

func sendPair(queue chan struct {string; int}) {
    queue <- struct {string; int}{"http:...", 3}
}

Anonymous structs and fields are fine for quick and dirty solutions like this. For all but the simplest cases though, you'd do better to define a named struct just like you did.

How to resize JLabel ImageIcon?

One (quick & dirty) way to resize images it to use HTML & specify the new size in the image element. This even works for animated images with transparency.

Use string in switch case in java

Java (before version 7) does not support String in switch/case. But you can achieve the desired result by using an enum.

private enum Fruit {
    apple, carrot, mango, orange;
}

String value; // assume input
Fruit fruit = Fruit.valueOf(value); // surround with try/catch

switch(fruit) {
    case apple:
        method1;
        break;
    case carrot:
        method2;
        break;
    // etc...
}

jQuery UI Dialog Box - does not open after being closed

I use the dialog as an dialog file browser and uploader then I rewrite the code like this

var dialog1 = $("#dialog").dialog({ 
              autoOpen: false, 
              height: 480, 
              width: 640 
}); 
$('#tikla').click(function() {  
    dialog1.load('./browser.php').dialog('open');
});   

everything seems to work great.

HTML form with side by side input fields

Put style="float:left" on each of your divs:

<div style="float:left;">...........

Example:

<div style="float:left;">
  <label for="username">First Name</label>
  <input id="user_first_name" name="user[first_name]" size="30" type="text" />
</div>

<div style="float:left;">
  <label for="name">Last Name</label>
  <input id="user_last_name" name="user[last_name]" size="30" type="text" />
</div>

To put an element on new line, put this div below it:

<div style="clear:both;">&nbsp;</div>

Of course, you can also create classes in the CSS file:

.left{
  float:left;
}

.clear{
  clear:both;
}

And then your html should look like this:

<div class="left">
  <label for="username">First Name</label>
  <input id="user_first_name" name="user[first_name]" size="30" type="text" />
</div>

<div class="left">
  <label for="name">Last Name</label>
  <input id="user_last_name" name="user[last_name]" size="30" type="text" />
</div>

To put an element on new line, put this div below it:

<div class="clear">&nbsp;</div>

More Info:

Maintain aspect ratio of div but fill screen width and height in CSS?

Use the new CSS viewport units vw and vh (viewport width / viewport height)

FIDDLE

Resize vertically and horizontally and you'll see that the element will always fill the maximum viewport size without breaking the ratio and without scrollbars!

(PURE) CSS

div
{
    width: 100vw; 
    height: 56.25vw; /* height:width ratio = 9/16 = .5625  */
    background: pink;
    max-height: 100vh;
    max-width: 177.78vh; /* 16/9 = 1.778 */
    margin: auto;
    position: absolute;
    top:0;bottom:0; /* vertical center */
    left:0;right:0; /* horizontal center */
}

_x000D_
_x000D_
* {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
div {_x000D_
  width: 100vw;_x000D_
  height: 56.25vw;_x000D_
  /* 100/56.25 = 1.778 */_x000D_
  background: pink;_x000D_
  max-height: 100vh;_x000D_
  max-width: 177.78vh;_x000D_
  /* 16/9 = 1.778 */_x000D_
  margin: auto;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  /* vertical center */_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  /* horizontal center */_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

If you want to use a maximum of say 90% width and height of the viewport: FIDDLE

_x000D_
_x000D_
* {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
div {_x000D_
  width: 90vw;_x000D_
  /* 90% of viewport vidth */_x000D_
  height: 50.625vw;_x000D_
  /* ratio = 9/16 * 90 = 50.625 */_x000D_
  background: pink;_x000D_
  max-height: 90vh;_x000D_
  max-width: 160vh;_x000D_
  /* 16/9 * 90 = 160 */_x000D_
  margin: auto;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

Also, browser support is pretty good too: IE9+, FF, Chrome, Safari- caniuse

How to determine previous page URL in Angular?

I had some struggle to access the previous url inside a guard.
Without implementing a custom solution, this one is working for me.

public constructor(private readonly router: Router) {
};

public ngOnInit() {
   this.router.getCurrentNavigation().previousNavigation.initialUrl.toString();
}

The initial url will be the previous url page.

MySQL Incorrect datetime value: '0000-00-00 00:00:00'

This is incredibly ugly, but it also fixed the problem quickly for me. Your table needs a unique key which you will use to fix the tainted columns. In this example, the primary key is called 'id' and the broken timestamp column is called 'BadColumn'.

  1. Select the IDs of the tainted columns.

    select id from table where BadColumn='0000-00-00 00:00:00'

  2. Collect the IDs into a comma-delimited string. Example: 1, 22, 33. I used an external wrapper for this (a Perl script) to quickly spit them all out.

  3. Use your list of IDs to update the old columns with a valid date (1971 through 2038).

    update table set BadColumn='2000-01-01 00:00:00' where id in (1, 22, 33)

cannot connect to pc-name\SQLEXPRESS

Initialize the SQL Server Browser Service.

How to convert an object to a byte array in C#

I believe what you're trying to do is impossible.

The junk that BinaryFormatter creates is necessary to recover the object from the file after your program stopped.
However it is possible to get the object data, you just need to know the exact size of it (more difficult than it sounds) :

public static unsafe byte[] Binarize(object obj, int size)
{
    var r = new byte[size];
    var rf = __makeref(obj);
    var a = **(IntPtr**)(&rf);
    Marshal.Copy(a, r, 0, size);
    return res;
}

this can be recovered via:

public unsafe static dynamic ToObject(byte[] bytes)
{
    var rf = __makeref(bytes);
    **(int**)(&rf) += 8;
    return GCHandle.Alloc(bytes).Target;
}

The reason why the above methods don't work for serialization is that the first four bytes in the returned data correspond to a RuntimeTypeHandle. The RuntimeTypeHandle describes the layout/type of the object but the value of it changes every time the program is ran.

EDIT: that is stupid don't do that --> If you already know the type of the object to be deserialized for certain you can switch those bytes for BitConvertes.GetBytes((int)typeof(yourtype).TypeHandle.Value) at the time of deserialization.

django MultiValueDictKeyError error, how do I deal with it

First check if the request object have the 'is_private' key parameter. Most of the case's this MultiValueDictKeyError occurred for missing key in the dictionary-like request object. Because dictionary is an unordered key, value pair “associative memories” or “associative arrays”

In another word. request.GET or request.POST is a dictionary-like object containing all request parameters. This is specific to Django.

The method get() returns a value for the given key if key is in the dictionary. If key is not available then returns default value None.

You can handle this error by putting :

is_private = request.POST.get('is_private', False);

How to change color in markdown cells ipython/jupyter notebook?

<span style='color:blue '> your message/text </span>

So here it is a perfect html css style entry inside a notebook ipynb file.

Of course you can choose your favourite color here and then your text.

Replace all 0 values to NA

Because someone asked for the Data.Table version of this, and because the given data.frame solution does not work with data.table, I am providing the solution below.

Basically, use the := operator --> DT[x == 0, x := NA]

library("data.table")

status = as.data.table(occupationalStatus)

head(status, 10)
    origin destination  N
 1:      1           1 50
 2:      2           1 16
 3:      3           1 12
 4:      4           1 11
 5:      5           1  2
 6:      6           1 12
 7:      7           1  0
 8:      8           1  0
 9:      1           2 19
10:      2           2 40


status[N == 0, N := NA]

head(status, 10)
    origin destination  N
 1:      1           1 50
 2:      2           1 16
 3:      3           1 12
 4:      4           1 11
 5:      5           1  2
 6:      6           1 12
 7:      7           1 NA
 8:      8           1 NA
 9:      1           2 19
10:      2           2 40

MessageBox Buttons?

if(DialogResult.OK==MessageBox.Show("Do you Agree with me???"))
{
         //do stuff if yess
}
else
{
         //do stuff if No
}

ModalPopupExtender OK Button click event not firing?

Aspx

<ajax:ModalPopupExtender runat="server" ID="modalPop" 
            PopupControlID="pnlpopup" 
            TargetControlID="btnGo"
              BackgroundCssClass="modalBackground"
             DropShadow="true"
             CancelControlID="btnCancel" X="470" Y="300"   />


//Codebehind    
protected void OkButton_Clicked(object sender, EventArgs e)
    {

        modalPop.Hide();
        //Do something in codebehind
    }

And don't set the OK button as OkControlID.

How to state in requirements.txt a direct github source

Since pip v1.5, (released Jan 1 2014: CHANGELOG, PR) you may also specify a subdirectory of a git repo to contain your module. The syntax looks like this:

pip install -e git+https://git.repo/some_repo.git#egg=my_subdir_pkg&subdirectory=my_subdir_pkg # install a python package from a repo subdirectory

Note: As a pip module author, ideally you'd probably want to publish your module in it's own top-level repo if you can. Yet this feature is helpful for some pre-existing repos that contain python modules in subdirectories. You might be forced to install them this way if they are not published to pypi too.

undefined offset PHP error

If preg_match did not find a match, $matches is an empty array. So you should check if preg_match found an match before accessing $matches[0], for example:

function get_match($regex,$content)
{
    if (preg_match($regex,$content,$matches)) {
        return $matches[0];
    } else {
        return null;
    }
}

How to flip background image using CSS?

You can flip both vertical and horizontal at the same time

    -moz-transform: scaleX(-1) scaleY(-1);
    -o-transform: scaleX(-1) scaleY(-1);
    -webkit-transform: scaleX(-1) scaleY(-1);
    transform: scaleX(-1) scaleY(-1);

And with the transition property you can get a cool flip

    -webkit-transition: transform .4s ease-out 0ms;
    -moz-transition: transform .4s ease-out 0ms;
    -o-transition: transform .4s ease-out 0ms;
    transition: transform .4s ease-out 0ms;
    transition-property: transform;
    transition-duration: .4s;
    transition-timing-function: ease-out;
    transition-delay: 0ms;

Actually it flips the whole element, not just the background-image

SNIPPET

_x000D_
_x000D_
function flip(){_x000D_
 var myDiv = document.getElementById('myDiv');_x000D_
 if (myDiv.className == 'myFlipedDiv'){_x000D_
  myDiv.className = '';_x000D_
 }else{_x000D_
  myDiv.className = 'myFlipedDiv';_x000D_
 }_x000D_
}
_x000D_
#myDiv{_x000D_
  display:inline-block;_x000D_
  width:200px;_x000D_
  height:20px;_x000D_
  padding:90px;_x000D_
  background-color:red;_x000D_
  text-align:center;_x000D_
  -webkit-transition:transform .4s ease-out 0ms;_x000D_
  -moz-transition:transform .4s ease-out 0ms;_x000D_
  -o-transition:transform .4s ease-out 0ms;_x000D_
  transition:transform .4s ease-out 0ms;_x000D_
  transition-property:transform;_x000D_
  transition-duration:.4s;_x000D_
  transition-timing-function:ease-out;_x000D_
  transition-delay:0ms;_x000D_
}_x000D_
.myFlipedDiv{_x000D_
  -moz-transform:scaleX(-1) scaleY(-1);_x000D_
  -o-transform:scaleX(-1) scaleY(-1);_x000D_
  -webkit-transform:scaleX(-1) scaleY(-1);_x000D_
  transform:scaleX(-1) scaleY(-1);_x000D_
}
_x000D_
<div id="myDiv">Some content here</div>_x000D_
_x000D_
<button onclick="flip()">Click to flip</button>
_x000D_
_x000D_
_x000D_

Static linking vs dynamic linking

Static linking includes the files that the program needs in a single executable file.

Dynamic linking is what you would consider the usual, it makes an executable that still requires DLLs and such to be in the same directory (or the DLLs could be in the system folder).

(DLL = dynamic link library)

Dynamically linked executables are compiled faster and aren't as resource-heavy.

Read a Csv file with powershell and capture corresponding data

So I figured out what is wrong with this statement:

Import-Csv H:\Programs\scripts\SomeText.csv |`

(Original)

Import-Csv H:\Programs\scripts\SomeText.csv -Delimiter "|"

(Proposed, You must use quotations; otherwise, it will not work and ISE will give you an error)

It requires the -Delimiter "|", in order for the variable to be populated with an array of items. Otherwise, Powershell ISE does not display the list of items.

I cannot say that I would recommend the | operator, since it is used to pipe cmdlets into one another.

I still cannot get the if statement to return true and output the values entered via the prompt.

If anyone else can help, it would be great. I still appreciate the post, it has been very helpful!

Copy or rsync command

For a local copy, the only advantage of rsync is that it will avoid copying if the file already exists in the destination directory. The definition of "already exists" is (a) same file name (b) same size (c) same timestamp. (Maybe same owner/group; I am not sure...)

The "rsync algorithm" is great for incremental updates of a file over a slow network link, but it will not buy you much for a local copy, as it needs to read the existing (partial) file to run it's "diff" computation.

So if you are running this sort of command frequently, and the set of changed files is small relative to the total number of files, you should find that rsync is faster than cp. (Also rsync has a --delete option that you might find useful.)

What is the best Java email address validation method?

Late answer, but I think it is simple and worthy:

    public boolean isValidEmailAddress(String email) {
           String ePattern = "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\])|(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,}))$";
           java.util.regex.Pattern p = java.util.regex.Pattern.compile(ePattern);
           java.util.regex.Matcher m = p.matcher(email);
           return m.matches();
    }

Test Cases:

enter image description here

For production purpose, Domain Name validations should be performed network-wise.

Moving from position A to position B slowly with animation

Use jquery animate and give it a long duration say 2000

$("#Friends").animate({ 
        top: "-=30px",
      }, duration );

The -= means that the animation will be relative to the current top position.

Note that the Friends element must have position set to relative in the css:

#Friends{position:relative;}

How to handle errors with boto3?

In case you have to deal with the arguably unfriendly logs client (CloudWatch Logs put-log-events), this is what I had to do to properly catch Boto3 client exceptions:

try:
    ### Boto3 client code here...

except boto_exceptions.ClientError as error:
    Log.warning("Catched client error code %s",
                error.response['Error']['Code'])

    if error.response['Error']['Code'] in ["DataAlreadyAcceptedException",
                                           "InvalidSequenceTokenException"]:
        Log.debug(
            "Fetching sequence_token from boto error response['Error']['Message'] %s",
            error.response["Error"]["Message"])
        # NOTE: apparently there's no sequenceToken attribute in the response so we have
        # to parse response["Error"]["Message"] string
        sequence_token = error.response["Error"]["Message"].split(":")[-1].strip(" ")
        Log.debug("Setting sequence_token to %s", sequence_token)

This works both at first attempt (with empty LogStream) and subsequent ones.

How do I create and read a value from cookie?

Mozilla provides a simple framework for reading and writing cookies with full unicode support along with examples of how to use it.

Once included on the page, you can set a cookie:

docCookies.setItem(name, value);

read a cookie:

docCookies.getItem(name);

or delete a cookie:

docCookies.removeItem(name);

For example:

// sets a cookie called 'myCookie' with value 'Chocolate Chip'
docCookies.setItem('myCookie', 'Chocolate Chip');

// reads the value of a cookie called 'myCookie' and assigns to variable
var myCookie = docCookies.getItem('myCookie');

// removes the cookie called 'myCookie'
docCookies.removeItem('myCookie');

See more examples and details on Mozilla's document.cookie page.

A version of this simple js file is on github.

Capturing URL parameters in request.GET

When a URL is like domain/search/?q=haha, you would use request.GET.get('q', '').

q is the parameter you want, and '' is the default value if q isn't found.

However, if you are instead just configuring your URLconf**, then your captures from the regex are passed to the function as arguments (or named arguments).

Such as:

(r'^user/(?P<username>\w{0,50})/$', views.profile_page,),

Then in your views.py you would have

def profile_page(request, username):
    # Rest of the method

How to make a flat list out of list of lists?

If you are willing to give up a tiny amount of speed for a cleaner look, then you could use numpy.concatenate().tolist() or numpy.concatenate().ravel().tolist():

import numpy

l = [[1, 2, 3], [4, 5, 6], [7], [8, 9]] * 99

%timeit numpy.concatenate(l).ravel().tolist()
1000 loops, best of 3: 313 µs per loop

%timeit numpy.concatenate(l).tolist()
1000 loops, best of 3: 312 µs per loop

%timeit [item for sublist in l for item in sublist]
1000 loops, best of 3: 31.5 µs per loop

You can find out more here in the docs numpy.concatenate and numpy.ravel

One line ftp server in python

apt-get install python3-pip

pip3 install pyftpdlib

python3 -m pyftpdlib -p 21 -w --user=username --password=password

-w = write permission

-p = desired port

--user = give your username

--password = give your password

How to implement history.back() in angular.js

Another nice and reusable solution is to create a directive like this:

app.directive( 'backButton', function() {
    return {
        restrict: 'A',
        link: function( scope, element, attrs ) {
            element.on( 'click', function () {
                history.back();
                scope.$apply();
            } );
        }
    };
} );

then just use it like this:

<a href back-button>back</a>

Error: No module named psycopg2.extensions

In python 3.4, while in a virtual environment, make sure you have the build dependencies first:

sudo apt-get build-dep python3-psycopg2

Then install it:

pip install psycopg2 

Internet Explorer 11 disable "display intranet sites in compatibility view" via meta tag not working

The question is a bit old but I just solved a very similar problem. We have several intranet sites here including the one I'm responsible for, and the others require compatibility mode or they break. For that reason, site rules default IE to compatibility mode on intranet sites. I am upgrading my own stuff and no longer need it; in fact, some of the features I'm trying to use don't look right in compat mode. I'm using the meta IE-Edge tag like you are.

IE assumes websites without the fully-qualified address are intranet, and acts accordingly. With that in mind I just altered the bindings in IIS to only listen to the fully-qualified address, then set up a dummy website that listened for the unqualified address. The second one redirects all traffic to the fully-qualified address, making IE believe it's an external site. The site renders correctly with or without the Compatibility Mode on Intranet Sites box checked.

Seedable JavaScript random number generator

If you don't need the seeding capability just use Math.random() and build helper functions around it (eg. randRange(start, end)).

I'm not sure what RNG you're using, but it's best to know and document it so you're aware of its characteristics and limitations.

Like Starkii said, Mersenne Twister is a good PRNG, but it isn't easy to implement. If you want to do it yourself try implementing a LCG - it's very easy, has decent randomness qualities (not as good as Mersenne Twister), and you can use some of the popular constants.

EDIT: consider the great options at this answer for short seedable RNG implementations, including an LCG option.

_x000D_
_x000D_
function RNG(seed) {_x000D_
  // LCG using GCC's constants_x000D_
  this.m = 0x80000000; // 2**31;_x000D_
  this.a = 1103515245;_x000D_
  this.c = 12345;_x000D_
_x000D_
  this.state = seed ? seed : Math.floor(Math.random() * (this.m - 1));_x000D_
}_x000D_
RNG.prototype.nextInt = function() {_x000D_
  this.state = (this.a * this.state + this.c) % this.m;_x000D_
  return this.state;_x000D_
}_x000D_
RNG.prototype.nextFloat = function() {_x000D_
  // returns in range [0,1]_x000D_
  return this.nextInt() / (this.m - 1);_x000D_
}_x000D_
RNG.prototype.nextRange = function(start, end) {_x000D_
  // returns in range [start, end): including start, excluding end_x000D_
  // can't modulu nextInt because of weak randomness in lower bits_x000D_
  var rangeSize = end - start;_x000D_
  var randomUnder1 = this.nextInt() / this.m;_x000D_
  return start + Math.floor(randomUnder1 * rangeSize);_x000D_
}_x000D_
RNG.prototype.choice = function(array) {_x000D_
  return array[this.nextRange(0, array.length)];_x000D_
}_x000D_
_x000D_
var rng = new RNG(20);_x000D_
for (var i = 0; i < 10; i++)_x000D_
  console.log(rng.nextRange(10, 50));_x000D_
_x000D_
var digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];_x000D_
for (var i = 0; i < 10; i++)_x000D_
  console.log(rng.choice(digits));
_x000D_
_x000D_
_x000D_

Most efficient way to map function over numpy array

All above answers compares well, but if you need to use custom function for mapping, and you have numpy.ndarray, and you need to retain the shape of array.

I have compare just two, but it will retain the shape of ndarray. I have used the array with 1 million entries for comparison. Here I use square function, which is also inbuilt in numpy and has great performance boost, since there as was need of something, you can use function of your choice.

import numpy, time
def timeit():
    y = numpy.arange(1000000)
    now = time.time()
    numpy.array([x * x for x in y.reshape(-1)]).reshape(y.shape)        
    print(time.time() - now)
    now = time.time()
    numpy.fromiter((x * x for x in y.reshape(-1)), y.dtype).reshape(y.shape)
    print(time.time() - now)
    now = time.time()
    numpy.square(y)  
    print(time.time() - now)

Output

>>> timeit()
1.162431240081787    # list comprehension and then building numpy array
1.0775556564331055   # from numpy.fromiter
0.002948284149169922 # using inbuilt function

here you can clearly see numpy.fromiter works great considering to simple approach, and if inbuilt function is available please use that.

How can I get the active screen dimensions?

Add on to ffpf

Screen.FromControl(this).Bounds

SQL Server 2008 - Help writing simple INSERT Trigger

You want to take advantage of the inserted logical table that is available in the context of a trigger. It matches the schema for the table that is being inserted to and includes the row(s) that will be inserted (in an update trigger you have access to the inserted and deleted logical tables which represent the the new and original data respectively.)

So to insert Employee / Department pairs that do not currently exist you might try something like the following.

CREATE TRIGGER trig_Update_Employee
ON [EmployeeResult]
FOR INSERT
AS
Begin
    Insert into Employee (Name, Department) 
    Select Distinct i.Name, i.Department 
    from Inserted i
    Left Join Employee e
    on i.Name = e.Name and i.Department = e.Department
    where e.Name is null
End

Apache redirect to another port

You have to make sure that the proxy is enabled on the server. You can do so by using the following commands:

  a2enmod proxy
  a2enmod proxy_http

  service apache2 restart

How can I trigger a JavaScript event click

.click() does not work with Android (look at mozilla docs, at mobile section). You can trigger the click event with this method:

function fireClick(node){
    if (document.createEvent) {
        var evt = document.createEvent('MouseEvents');
        evt.initEvent('click', true, false);
        node.dispatchEvent(evt);    
    } else if (document.createEventObject) {
        node.fireEvent('onclick') ; 
    } else if (typeof node.onclick == 'function') {
        node.onclick(); 
    }
}

From this post

Alter a MySQL column to be AUTO_INCREMENT

You must specify the type of the column before the auto_increment directive, i.e. ALTER TABLE document MODIFY COLUMN document_id INT AUTO_INCREMENT.

Formatting code snippets for blogging on Blogger

I use SyntaxHighlighter with my Blogger powered blog. The actual site is hosted on my own server rather than Blogger's though (Blogger has an option of ftping posts to your own site), but having your own domain and web hosting only costs a couple of dollars a month.

What charset does Microsoft Excel use when saving files?

I had a similar problem last week. I received a number of CSV files with varying encodings. Before importing into the database I then used the chardet libary to automatically sniff out the correct encoding.

Chardet is a port from Mozillas character detection engine and if the sample size is large enough (one accentuated character will not do) works really well.

how to overcome ERROR 1045 (28000): Access denied for user 'ODBC'@'localhost' (using password: NO) permanently

i entered in Mysql Workbench and i changed the password. It seem the password was expired. it works!

500 Internal Server Error for php file not for html

I know this question is old, however I ran into this problem on Windows 8.1 while trying to use .htaccess files for rewriting. My solution was simple, I forgot to modify the following line in httpd.conf

#LoadModule rewrite_module modules/mod_rewrite.so

to

LoadModule rewrite_module modules/mod_rewrite.so

Restarted the apache monitor, now all works well. Just posting this as an answer because someone in the future may run across the same issue with a simple fix.

Good luck!

How to set background color of an Activity to white programmatically?

?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF"
android:id="@+id/myScreen"
</LinearLayout>

In other words, "android:background" is the tag in the XML you want to change.

If you need to dynamically update the background value, see the following:

Exercise: Change background color, by SeekBar

Extracting time from POSIXct

The time_t value for midnight GMT is always divisible by 86400 (24 * 3600). The value for seconds-since-midnight GMT is thus time %% 86400.

The hour in GMT is (time %% 86400) / 3600 and this can be used as the x-axis of the plot:

plot((as.numeric(times) %% 86400)/3600, val)

enter image description here

To adjust for a time zone, adjust the time before taking the modulus, by adding the number of seconds that your time zone is ahead of GMT. For example, US central daylight saving time (CDT) is 5 hours behind GMT. To plot against the time in CDT, the following expression is used:

plot(((as.numeric(times) - 5*3600) %% 86400)/3600, val)

Can't get Gulp to run: cannot find module 'gulp-util'

You should install these as devDependencies:
- gulp-util
- gulp-load-plugins

Then, you can use them either this way:

var plugins     = require('gulp-load-plugins')();
Use gulp-util as : plugins.util()

or this:

var util = require('gulp-util')

HTML5 event handling(onfocus and onfocusout) using angular 2

Try to use (focus) and (focusout) instead of onfocus and onfocusout

like this : -

<input name="date" type="text" (focus)="focusFunction()" (focusout)="focusOutFunction()">

also you can use like this :-

some people prefer the on- prefix alternative, known as the canonical form:

<input name="date" type="text" on-focus="focusFunction()" on-focusout="focusOutFunction()">

Know more about event binding see here.

you have to use HostListner for your use case

Angular will invoke the decorated method when the host element emits the specified event.@HostListener is a decorator for the callback/event handler method

See my Update working Plunker.

Working Example Working Stackblitz

Update

Some other events can be used in angular -

(focus)="myMethod()"
(blur)="myMethod()" 
(submit)="myMethod()"  
(scroll)="myMethod()"

What is the Auto-Alignment Shortcut Key in Eclipse?

Ctrl+Shift+F to invoke the Auto Formatter

Ctrl+I to indent the selected part (or all) of you code.

Wrapping a react-router Link in an html button

With styled components this can be easily achieved

First Design a styled button

import styled from "styled-components";
import {Link} from "react-router-dom";

const Button = styled.button`
  background: white;
  color:red;
  font-size: 1em;
  margin: 1em;
  padding: 0.25em 1em;
  border: 2px solid red;
  border-radius: 3px;
`
render(
    <Button as={Link} to="/home"> Text Goes Here </Button>
);

check styled component's home for more

Input type DateTime - Value format?

For what it's worth, with iOS7 dropping support for datetime you need to use datetime-local which doesn't accept timezone portion (which makes sense).

Doesn't work (iOS anyway):

 <input type="datetime-local" value="2000-01-01T00:00:00+05:00" />

Works:

<input type="datetime-local" value="2000-01-01T00:00:00" />

PHP for value (windows safe):

strftime('%Y-%m-%dT%H:%M:%S', strtotime($my_datetime_input))

Is there a JavaScript / jQuery DOM change listener?

In addition to the "raw" tools provided by MutationObserver API, there exist "convenience" libraries to work with DOM mutations.

Consider: MutationObserver represents each DOM change in terms of subtrees. So if you're, for instance, waiting for a certain element to be inserted, it may be deep inside the children of mutations.mutation[i].addedNodes[j].

Another problem is when your own code, in reaction to mutations, changes DOM - you often want to filter it out.

A good convenience library that solves such problems is mutation-summary (disclaimer: I'm not the author, just a satisfied user), which enables you to specify queries of what you're interested in, and get exactly that.

Basic usage example from the docs:

var observer = new MutationSummary({
  callback: updateWidgets,
  queries: [{
    element: '[data-widget]'
  }]
});

function updateWidgets(summaries) {
  var widgetSummary = summaries[0];
  widgetSummary.added.forEach(buildNewWidget);
  widgetSummary.removed.forEach(cleanupExistingWidget);
}

How to wait in a batch script?

Well, does sleep even exist on your Windows XP box? According to this post: http://malektips.com/xp_dos_0002.html sleep isn't available on Windows XP, and you have to download the Windows 2003 Resource Kit in order to get it.

Chakrit's answer gives you another way to pause, too.

Try running sleep 10 from a command prompt.

Bootstrap 4 img-circle class not working

It's now called rounded-circle as explained here in the BS4 docs

<img src="img/gallery2.JPG" class="rounded-circle">

Demo

RegEx to make sure that the string contains at least one lower case char, upper case char, digit and symbol

Bart Kiers, your regex has a couple issues. The best way to do that is this:

(.*[a-z].*)       // For lower cases
(.*[A-Z].*)       // For upper cases
(.*\d.*)          // For digits

In this way you are searching no matter if at the beginning, at the end or at the middle. In your have I have a lot of troubles with complex passwords.

Where can I read the Console output in Visual Studio 2015

You can run your program by: Debug -> Start Without Debugging. It will keep a console opened after the program will be finished.

enter image description here

How to auto adjust the div size for all mobile / tablet display formats?

I don't have much time and your jsfidle did not work right now.
But maybe this will help you getting started.

First of all you should avoid to put css in your html tags. Like align="center".
Put stuff like that in your css since it is much clearer and won't deprecate that fast.

If you want to design responsive layouts you should use media queries wich were introduced in css3 and are supported very well by now.

Example css:

@media screen and (min-width: 100px) and (max-width: 199px)
{
    .button
    {
        width: 25px;
    }
}

@media screen and (min-width: 200px) and (max-width: 299px)
{
    .button
    {
        width: 50px;
    }
}

You can use any css you want inside a media query.
http://www.w3.org/TR/css3-mediaqueries/

How do you stop MySQL on a Mac OS install?

Apparently you want:

sudo /Library/StartupItems/MySQLCOM/MySQLCOM stop

Have a further read in Jeez People, Stop Fretting Over Installing RMagic.

How to Run a jQuery or JavaScript Before Page Start to Load

Maybe you are using:

$(document).ready(function(){
   // Your code here
 });

Try this instead:

window.onload = function(){  }

jQuery disable/enable submit button

We can simply have if & else .if suppose your input is empty we can have

if($(#name).val() != '') {
   $('input[type="submit"]').attr('disabled' , false);
}

else we can change false into true

Java error: Comparison method violates its general contract

Consider the following case:

First, o1.compareTo(o2) is called. card1.getSet() == card2.getSet() happens to be true and so is card1.getRarity() < card2.getRarity(), so you return 1.

Then, o2.compareTo(o1) is called. Again, card1.getSet() == card2.getSet() is true. Then, you skip to the following else, then card1.getId() == card2.getId() happens to be true, and so is cardType > item.getCardType(). You return 1 again.

From that, o1 > o2, and o2 > o1. You broke the contract.

How to use ClassLoader.getResources() correctly?

Here is code based on bestsss' answer:

    Enumeration<URL> en = getClass().getClassLoader().getResources(
            "META-INF");
    List<String> profiles = new ArrayList<>();
    while (en.hasMoreElements()) {
        URL url = en.nextElement();
        JarURLConnection urlcon = (JarURLConnection) (url.openConnection());
        try (JarFile jar = urlcon.getJarFile();) {
            Enumeration<JarEntry> entries = jar.entries();
            while (entries.hasMoreElements()) {
                String entry = entries.nextElement().getName();
                System.out.println(entry);
            }
        }
    }

What is the ellipsis (...) for in this method signature?

Those are Java varargs. They let you pass any number of objects of a specific type (in this case they are of type JID).

In your example, the following function calls would be valid:

MessageBuilder msgBuilder; //There should probably be a call to a constructor here ;)
MessageBuilder msgBuilder2;
msgBuilder.withRecipientJids(jid1, jid2);
msgBuilder2.withRecipientJids(jid1, jid2, jid78_a, someOtherJid);

See more here: http://java.sun.com/j2se/1.5.0/docs/guide/language/varargs.html

Extract file name from path, no matter what the os/path format

In your example you will also need to strip slash from right the right side to return c:

>>> import os
>>> path = 'a/b/c/'
>>> path = path.rstrip(os.sep) # strip the slash from the right side
>>> os.path.basename(path)
'c'

Second level:

>>> os.path.filename(os.path.dirname(path))
'b'

update: I think lazyr has provided the right answer. My code will not work with windows-like paths on unix systems and vice versus with unix-like paths on windows system.

C# how to wait for a webpage to finish loading before continuing

Check out the WatiN project:

Inspired by Watir development of WatiN started in December 2005 to make a similar kind of Web Application Testing possible for the .Net languages. Since then WatiN has grown into an easy to use, feature rich and stable framework. WatiN is developed in C# and aims to bring you an easy way to automate your tests with Internet Explorer and FireFox using .Net...

String.replaceAll single backslashes with double backslashes

TLDR: use theString = theString.replace("\\", "\\\\"); instead.


Problem

replaceAll(target, replacement) uses regular expression (regex) syntax for target and partially for replacement.

Problem is that \ is special character in regex (it can be used like \d to represents digit) and in String literal (it can be used like "\n" to represent line separator or \" to escape double quote symbol which normally would represent end of string literal).

In both these cases to create \ symbol we can escape it (make it literal instead of special character) by placing additional \ before it (like we escape " in string literals via \").

So to target regex representing \ symbol will need to hold \\, and string literal representing such text will need to look like "\\\\".

So we escaped \ twice:

  • once in regex \\
  • once in String literal "\\\\" (each \ is represented as "\\").

In case of replacement \ is also special there. It allows us to escape other special character $ which via $x notation, allows us to use portion of data matched by regex and held by capturing group indexed as x, like "012".replaceAll("(\\d)", "$1$1") will match each digit, place it in capturing group 1 and $1$1 will replace it with its two copies (it will duplicate it) resulting in "001122".

So again, to let replacement represent \ literal we need to escape it with additional \ which means that:

  • replacement must hold two backslash characters \\
  • and String literal which represents \\ looks like "\\\\"

BUT since we want replacement to hold two backslashes we will need "\\\\\\\\" (each \ represented by one "\\\\").

So version with replaceAll can look like

replaceAll("\\\\", "\\\\\\\\");

Easier way

To make out life easier Java provides tools to automatically escape text into target and replacement parts. So now we can focus only on strings, and forget about regex syntax:

replaceAll(Pattern.quote(target), Matcher.quoteReplacement(replacement))

which in our case can look like

replaceAll(Pattern.quote("\\"), Matcher.quoteReplacement("\\\\"))

Even better

If we don't really need regex syntax support lets not involve replaceAll at all. Instead lets use replace. Both methods will replace all targets, but replace doesn't involve regex syntax. So you could simply write

theString = theString.replace("\\", "\\\\");

How do you read a file into a list in Python?

The pythonic way to read a file and put every lines in a list:

from __future__ import with_statement #for python 2.5
with open('C:/path/numbers.txt', 'r') as f:
    lines = f.readlines()

Then, assuming that each lines contains a number,

numbers =[int(e.strip()) for e in lines]

How do I fit an image (img) inside a div and keep the aspect ratio?

I was having a lot of problems to get this working, every single solution I found didn't seem to work.

I realized that I had to set the div display to flex, so basically this is my CSS:

div{
display: flex;
}

div img{ 
max-height: 100%;
max-width: 100%;
}

Resizing an Image without losing any quality

Here is a forum thread that provides a C# image resizing code sample. You could use one of the GD library binders to do resampling in C#.

Change the current directory from a Bash script

Basically we use cd.. to come back from every directory. I thought to make it more easy by giving the number of directories with which you need to come back at a time. You can implement this using a separate script file using the alias command . For example:

code.sh

#!/bin/sh
 _backfunc(){
 if [ "$1" -eq 1 ]; then
  cd ..
 elif [ "$1" -eq 2 ]; then
  cd ../..
 elif [ "$1" -eq 3 ]; then
  cd ../../..
 elif [ "$1" -eq 4 ]; then
  cd ../../../..
 elif ["$1" -eq 10]; then
  cd /home/arun/Documents/work
 fi
 }
alias back='_backfunc'   

After using source code.sh in the current shell you can use :

$back 2 

to come two steps back from the current directory. Explained in detail over here. It is also explained over there how to put the code in ~/.bashrc so that every new shell opened will automatically have this new alias command. You can add new command to go to specific directories by modifying the code by adding more if conditions and different arguments. You can also pull the code from git over here.

remove attribute display:none; so the item will be visible

The jQuery you're using is manipulates the DOM, not the CSS itself. Try changing the word span in your CSS to .mySpan, then apply that class to one or more DOM elements in your HTML like so:

...
<span class="mySpan">...</span>
...

Then, change your jQuery as follows:

$(".mySpan").css({ display : inline });

This should work much better.

Good luck!

How to autoplay HTML5 mp4 video on Android?

Autoplay only works the second time through. on android 4.1+ you have to have some kind of user event to get the first play() to work. Once that has happened then autostart works.

This is so that the user is acknowledging that they are using bandwidth.

There is another question that answers this . Autostart html5 video using android 4 browser

Print the contents of a DIV

Here is my jquery print plugin

(function ($) {

$.fn.printme = function () {
    return this.each(function () {
        var container = $(this);

        var hidden_IFrame = $('<iframe></iframe>').attr({
            width: '1px',
            height: '1px',
            display: 'none'
        }).appendTo(container);

        var myIframe = hidden_IFrame.get(0);

        var script_tag = myIframe.contentWindow.document.createElement("script");
        script_tag.type = "text/javascript";
        script = myIframe.contentWindow.document.createTextNode('function Print(){ window.print(); }');
        script_tag.appendChild(script);

        myIframe.contentWindow.document.body.innerHTML = container.html();
        myIframe.contentWindow.document.body.appendChild(script_tag);

        myIframe.contentWindow.Print();
        hidden_IFrame.remove();

    });
};
})(jQuery);

Change tab bar tint color on iOS 7

You can set your tint color and font as setTitleTextattribute:

UIFont *font= (kUIScreenHeight>KipadHeight)?[UIFont boldSystemFontOfSize:32.0f]:[UIFont boldSystemFontOfSize:16.0f];
NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName,
                            tintColorLight, NSForegroundColorAttributeName, nil];
[[UINavigationBar appearance] setTitleTextAttributes:attributes];

Jquery Change Height based on Browser Size/Resize

$(function(){
    $(window).resize(function(){
        var h = $(window).height();
        var w = $(window).width();
        $("#elementToResize").css('height',(h < 768 || w < 1024) ? 500 : 400);
    });
});

Scrollbars etc have an effect on the window size so you may want to tweak to desired size.

A server with the specified hostname could not be found

I faced the same problem, it turned out to be VPN related. If you are testing on a device against a corporate network, chances are your Mac has proper VPN set up, but your phone does not. Connect phone to the corporate VPN for your apps deployed to device to see corporate servers.

Can you force Visual Studio to always run as an Administrator in Windows 8?

I know this is a little late, but I just figured out how to do this by modifying (read, "hacking") the manifest of the devenv.exe file. I should have come here first because the stated solutions seem a little easier, and probably more supported by Microsoft. :)

Here's how I did it:

  1. Create a project in VS called "Exe Manifests". (I think any version will work, but I used 2013 Pro. Also, it doesn't really matter what you name it.)
  2. "Add existing item" to the project, browse to the Visual Studio exe, and click Okay. In my case, it was "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe".
  3. Double-click on the "devenv.exe" file that should now be listed as a file in your project. It should bring up the exe in a resource editor.
  4. Expand the "RT_MANIFEST" node, then double-click on "1" under that. This will open up the executable's manifest in the binary editor.
  5. Find the requestedExecutionLevel tag and replace "asInvoker" with "requireAdministrator". A la: <requestedExecutionLevel level="requireAdministrator" uiAccess="false"></requestedExecutionLevel>
  6. Save the file.

You've just saved the copy of the executable that was added to your project. Now you need to back up the original and copy your modified exe to your installation directory.

As I said, this is probably not the right way to do it, but it seems to work. If anyone knows of any negative fallout or requisite wrist-slapping that needs to happen, please chime in!

MySQL Insert into multiple tables? (Database normalization?)

This is the way that I did it for a uni project, works fine, prob not safe tho

$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);

$title =    $_POST['title'];            
$name =     $_POST['name'];         
$surname =  $_POST['surname'];                  
$email =    $_POST['email'];            
$pass =     $_POST['password'];     
$cpass =    $_POST['cpassword'];        

$check = 1;

if (){
}
else{
    $check = 1;
}   
if ($check == 1){

require_once('website_data_collecting/db.php');

$sel_user = "SELECT * FROM users WHERE user_email='$email'";
$run_user = mysqli_query($con, $sel_user);
$check_user = mysqli_num_rows($run_user);

if ($check_user > 0){
    echo    '<div style="margin: 0 0 10px 20px;">Email already exists!</br>
             <a href="recover.php">Recover Password</a></div>';
}
else{
    $users_tb = "INSERT INTO users ". 
           "(user_name, user_email, user_password) ". 
        "VALUES('$name','$email','$pass')";

    $users_info_tb = "INSERT INTO users_info".
           "(user_title, user_surname)".
        "VALUES('$title', '$surname')";

    mysql_select_db('dropbox');
    $run_users_tb = mysql_query( $users_tb, $conn );
    $run_users_info_tb = mysql_query( $users_info_tb, $conn );

    if(!$run_users_tb || !$run_users_info_tb){
        die('Could not enter data: ' . mysql_error());
    }
    else{
        echo "Entered data successfully\n";
    }

    mysql_close($conn);
}

}

Android Studio shortcuts like Eclipse

Save all Control + S Command + S

Synchronize Control + Alt + Y Command + Option + Y

Maximize/minimize editor Control + Shift + F12 Control + Command + F12

Add to favorites Alt + Shift + F Option + Shift + F

Inspect current file with current profile Alt + Shift + I Option + Shift + I

Quick switch scheme Control + (backquote) Control + (backquote)

Open settings dialogue Control + Alt + S Command + , (comma)

Open project structure dialog Control + Alt + Shift + S Command + ; (semicolon)

Switch between tabs and tool window Control + Tab Control + Tab

Navigating and searching within Studio

Search everything (including code and menus) Press Shift twice Press Shift twice

Find Control + F Command + F

Find next F3 Command + G

Find previous Shift + F3 Command + Shift + G

Replace Control + R Command + R

Find action Control + Shift + A Command + Shift + A

Search by symbol name Control + Alt + Shift + N Command + Option + O

Find class Control + N Command + O

Find file (instead of class) Control + Shift + N Command + Shift + O

Find in path Control + Shift + F Command + Shift + F

Open file structure pop-up Control + F12 Command + F12

Navigate between open editor tabs Alt + Right/Left Arrow Control + Right/Left Arrow

Jump to source F4 / Control + Enter F4 / Command + Down Arrow

Open current editor tab in new window Shift + F4 Shift + F4

Recently opened files pop-up Control + E Command + E

Recently edited files pop-up Control + Shift + E Command + Shift + E

Go to last edit location Control + Shift + Backspace Command + Shift + Backspace

Close active editor tab Control + F4 Command + W

Return to editor window from a tool window Esc Esc

Hide active or last active tool window Shift + Esc Shift + Esc

Go to line Control + G Command + L

Open type hierarchy Control + H Control + H

Open method hierarchy Control + Shift + H Command + Shift + H

Open call hierarchy Control + Alt + H Control + Option + H

Writing code

Generate code (getters, setters, constructors, hashCode/equals, toString, new file, new class) Alt + Insert Command + N

Override methods Control + O Control + O

Implement methods Control + I Control + I

Surround with (if...else / try...catch / etc.) Control + Alt + T Command + Option + T

Delete line at caret Control + Y Command + Backspace

Collapse/expand current code block Control + minus/plus Command + minus/plus Collapse/expand all code blocks Control + Shift + minus/plus Command + Shift +

minus/plus

Duplicate current line or selection Control + D Command + D

Basic code completion Control + Space Control + Space

Smart code completion (filters the list of methods and variables by expected type)
Control + Shift + Space Control + Shift + Space

Complete statement Control + Shift + Enter Command + Shift + Enter

Quick documentation lookup Control + Q Control + J

Show parameters for selected method Control + P Command + P

Go to declaration (directly) Control + B or Control + Click Command + B or Command + Click

Go to implementations Control + Alt + B Command + Alt + B

Go to super-method/super-class Control + U Command + U

Open quick definition lookup Control + Shift + I Command + Y

Toggle project tool window visibility Alt + 1 Command + 1

Toggle bookmark F11 F3

Toggle bookmark with mnemonic Control + F11 Option + F3

Comment/uncomment with line comment Control + / Command + /

Comment/uncomment with block comment Control + Shift + / Command + Shift + /

Select successively increasing code blocks Control + W Option + Up

Decrease current selection to previous state Control + Shift + W Option + Down

Move to code block start Control + [ Option + Command + [

Move to code block end Control + ] Option + Command + ]

Select to the code block start Control + Shift + [ Option + Command + Shift + [

Select to the code block end Control + Shift + ] Option + Command + Shift + ]

Delete to end of word Control + Delete Option + Delete

Delete to start of word Control + Backspace Option + Backspace

Optimize imports Control + Alt + O Control + Option + O

Project quick fix (show intention actions and quick fixes) Alt + Enter Option + Enter

Reformat code Control + Alt + L Command + Option + L

Auto-indent lines Control + Alt + I Control + Option + I

Indent/unindent lines Tab/Shift + Tab Tab/Shift + Tab

Smart line join Control + Shift + J Control + Shift + J

Smart line split Control + Enter Command + Enter

Start new line Shift + Enter Shift + Enter

Next/previous highlighted error F2 / Shift + F2 F2 / Shift + F2

Build and run

Build Control + F9 Command + F9

Build and run Shift + F10 Control + R

Apply changes (with Instant Run) Control + F10 Control + Command + R

Debugging

Debug Shift + F9 Control + D

Step over F8 F8

Step into F7 F7

Smart step into Shift + F7 Shift + F7

Step out Shift + F8 Shift + F8

Run to cursor Alt + F9 Option + F9

Evaluate expression Alt + F8 Option + F8

Resume program F9 Command + Option + R

Toggle breakpoint Control + F8 Command + F8

View breakpoints Control + Shift + F8 Command + Shift + F8

Refactoring

Copy F5 F5

Move F6 F6

Safe delete Alt + Delete Command + Delete

Rename Shift + F6 Shift + F6

Change signature Control + F6 Command + F6

Inline Control + Alt + N Command + Option + N

Extract method Control + Alt + M Command + Option + M

Extract variable Control + Alt + V Command + Option + V

Extract field Control + Alt + F Command + Option + F

Extract constant Control + Alt + C Command + Option + C

Extract parameter Control + Alt + P Command + Option + P

Version control / local history

Commit project to VCS Control + K Command + K

Update project from VCS Control + T Command + T

View recent changes Alt + Shift + C Option + Shift + C

Open VCS popup Alt + ` (backquote) Control + V

Is there a Java API that can create rich Word documents?

iText is really easy to use.

If you requiere doc files you can call abiword (free lightweigh multi-os text procesor) from the command line, it has several conversion format convert options.

Has Facebook sharer.php changed to no longer accept detailed parameters?

If you encode the & in your URL to %26 it works correctly. Just tested and verified.

Create empty data frame with column names by assigning a string vector?

How about:

df <- data.frame(matrix(ncol = 3, nrow = 0))
x <- c("name", "age", "gender")
colnames(df) <- x

To do all these operations in one-liner:

setNames(data.frame(matrix(ncol = 3, nrow = 0)), c("name", "age", "gender"))

#[1] name   age    gender
#<0 rows> (or 0-length row.names)

Or

data.frame(matrix(ncol=3,nrow=0, dimnames=list(NULL, c("name", "age", "gender"))))

HTTP Status 500 - Error instantiating servlet class pkg.coreServlet

The above error can occur for multiple cases during servlet startup / request. Hope you check the full stack trace of the server log, If you have tomcat, you can also see the exact causes in html preview of the 500 Internal Server Error page.

Weird thing is, if you try to hit the request url a second time, you would get 404 Not Found page.

You can also debug this issue, by placing breakpoints on all the classes constructor initialization block, whose objects are created during servlet startup/request.

In my case, I didn't had javaassist jar loaded for the Weld CDI injection to work. And it shown NoClassDefFound Error.

Why is `input` in Python 3 throwing NameError: name... is not defined

I'd say the code you need is:

test = input("enter the test")
print(test)

Otherwise it shouldn't run at all, due to a syntax error. The print function requires brackets in python 3. I cannot reproduce your error, though. Are you sure it's those lines causing that error?

How to play a sound using Swift?

Game style:

file Sfx.swift

import AVFoundation

public let sfx = Sfx.shared
public final class Sfx: NSObject {
    
    static let shared = Sfx()
    
    var apCheer: AVAudioPlayer? = nil
    
    private override init() {
        guard let s = Bundle.main.path(forResource: "cheer", ofType: "mp3") else {
            return  print("Sfx woe")
        }
        do {
            apComment = try AVAudioPlayer(contentsOf: URL(fileURLWithPath: s))
        } catch {
            return  print("Sfx woe")
        }
    }
    
    func cheer() { apCheer?.play() }
    func plonk() { apPlonk?.play() }
    func crack() { apCrack?.play() } .. etc
}

Anywhere at all in code

sfx.explosion()
sfx.cheer()

Setting CSS pseudo-class rules from JavaScript

One option you could consider is using CSS variables. The idea is that you set the property you want to change to a CSS variable. Then, within your JS, change that variable's value.

See example below

_x000D_
_x000D_
function changeColor(newColor) {
  document.documentElement.style.setProperty("--anchor-hover-color", newColor);
  // ^^^^^^^^^^^-- select the root 
}
_x000D_
:root {
  --anchor-hover-color: red;
}

a:hover { 
  color: var(--anchor-hover-color); 
}
_x000D_
<a href="#">Hover over me</a>

<button onclick="changeColor('lime')">Change to lime</button>
<button onclick="changeColor('red')">Change to red</button>
_x000D_
_x000D_
_x000D_

JavaScript global event mechanism

Try Atatus which provides Advanced Error Tracking and Real User Monitoring for modern web apps.

https://www.atatus.com/

Let me explain how to get stacktraces that are reasonably complete in all browsers.

Error handling in JavaScript

Modern Chrome and Opera fully support the HTML 5 draft spec for ErrorEvent and window.onerror. In both of these browsers you can either use window.onerror, or bind to the 'error' event properly:

// Only Chrome & Opera pass the error object.
window.onerror = function (message, file, line, col, error) {
    console.log(message, "from", error.stack);
    // You can send data to your server
    // sendError(data);
};
// Only Chrome & Opera have an error attribute on the event.
window.addEventListener("error", function (e) {
    console.log(e.error.message, "from", e.error.stack);
    // You can send data to your server
    // sendError(data);
})

Unfortunately Firefox, Safari and IE are still around and we have to support them too. As the stacktrace is not available in window.onerror we have to do a little bit more work.

It turns out that the only thing we can do to get stacktraces from errors is to wrap all of our code in a try{ }catch(e){ } block and then look at e.stack. We can make the process somewhat easier with a function called wrap that takes a function and returns a new function with good error handling.

function wrap(func) {
    // Ensure we only wrap the function once.
    if (!func._wrapped) {
        func._wrapped = function () {
            try{
                func.apply(this, arguments);
            } catch(e) {
                console.log(e.message, "from", e.stack);
                // You can send data to your server
                // sendError(data);
                throw e;
            }
        }
    }
    return func._wrapped;
};

This works. Any function that you wrap manually will have good error handling, but it turns out that we can actually do it for you automatically in most cases.

By changing the global definition of addEventListener so that it automatically wraps the callback we can automatically insert try{ }catch(e){ } around most code. This lets existing code continue to work, but adds high-quality exception tracking.

var addEventListener = window.EventTarget.prototype.addEventListener;
window.EventTarget.prototype.addEventListener = function (event, callback, bubble) {
    addEventListener.call(this, event, wrap(callback), bubble);
}

We also need to make sure that removeEventListener keeps working. At the moment it won't because the argument to addEventListener is changed. Again we only need to fix this on the prototype object:

var removeEventListener = window.EventTarget.prototype.removeEventListener;
window.EventTarget.prototype.removeEventListener = function (event, callback, bubble) {
    removeEventListener.call(this, event, callback._wrapped || callback, bubble);
}

Transmit error data to your backend

You can send error data using image tag as follows

function sendError(data) {
    var img = newImage(),
        src = 'http://yourserver.com/jserror&data=' + encodeURIComponent(JSON.stringify(data));

    img.crossOrigin = 'anonymous';
    img.onload = function success() {
        console.log('success', data);
    };
    img.onerror = img.onabort = function failure() {
        console.error('failure', data);
    };
    img.src = src;
}

Disclaimer: I am a web developer at https://www.atatus.com/.

Get Number of Rows returned by ResultSet in Java

You may think JDBC is a rich API and ResultSet has got so many methods then why not just a getCount() method? Well, For many databases e.g. Oracle, MySQL and SQL Server, ResultSet is a streaming API, this means that it does not load (or maybe even fetch) all the rows from the database server. By iterating to the end of the ResultSet you may add significantly to the time taken to execute in certain cases.

Btw, if you have to there are a couple of ways to do it e.g. by using ResultSet.last() and ResultSet.getRow() method, that's not the best way to do it but it works if you absolutely need it.

Though, getting the column count from a ResultSet is easy in Java. The JDBC API provides a ResultSetMetaData class which contains methods to return the number of columns returned by a query and hold by ResultSet.

How to round a number to significant figures in Python

If you want to have other than 1 significant decimal (otherwise the same as Evgeny):

>>> from math import log10, floor
>>> def round_sig(x, sig=2):
...   return round(x, sig-int(floor(log10(abs(x))))-1)
... 
>>> round_sig(0.0232)
0.023
>>> round_sig(0.0232, 1)
0.02
>>> round_sig(1234243, 3)
1230000.0

Conda update failed: SSL error: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed

Conda needs to know where to find you SSL certificate store.

conda config --set ssl_verify <pathToYourFile>.crt

No need to disable SSL verification.

This command add a line to your $HOME/.condarc file or %USERPROFILE%\.condarc file on Windows that looks like:

ssl_verify: <pathToYourFile>.crt

If you leave your organization's network, you can just comment out that line in .condarc with a # and uncomment when you return.

If it still doesn't work, make sure that you are using the latest version of curl, checking both the conda-forge and anaconda channels.

Add timestamp column with default NOW() for new rows only

You could add the default rule with the alter table,

ALTER TABLE mytable ADD COLUMN created_at TIMESTAMP DEFAULT NOW()

then immediately set to null all the current existing rows:

UPDATE mytable SET created_at = NULL

Then from this point on the DEFAULT will take effect.

Make page to tell browser not to cache/preserve input values

This worked for me in newer browsers:

autocomplete="new-password"

Python append() vs. + operator on lists, why do these give different results?

append is appending an element to a list. if you want to extend the list with the new list you need to use extend.

>>> c = [1, 2, 3]
>>> c.extend(c)
>>> c
[1, 2, 3, 1, 2, 3]

Difference between maven scope compile and provided for JAR packaging

If you're planning to generate a single JAR file with all of its dependencies (the typical xxxx-all.jar), then provided scope matters, because the classes inside this scope won't be package in the resulting JAR.

See maven-assembly-plugin for more information

Cannot find libcrypto in Ubuntu

I solved this on 12.10 by installing libssl-dev.

sudo apt-get install libssl-dev

How to determine the encoding of text?

This might be helpful

from bs4 import UnicodeDammit
with open('automate_data/billboard.csv', 'rb') as file:
   content = file.read()

suggestion = UnicodeDammit(content)
suggestion.original_encoding
#'iso-8859-1'

Should I write script in the body or the head of the html?

I would answer this with multiple options actually, the some of which actually render in the body.

  • Place library script such as the jQuery library in the head section.
  • Place normal script in the head unless it becomes a performance/page load issue.
  • Place script associated with includes, within and at the end of that include. One example of this is .ascx user controls in asp.net pages - place the script at the end of that markup.
  • Place script that impacts the render of the page at the end of the body (before the body closure).
  • do NOT place script in the markup such as <input onclick="myfunction()"/> - better to put it in event handlers in your script body instead.
  • If you cannot decide, put it in the head until you have a reason not to such as page blocking issues.

Footnote: "When you need it and not prior" applies to the last item when page blocking (perceptual loading speed). The user's perception is their reality—if it is perceived to load faster, it does load faster (even though stuff might still be occurring in code).

EDIT: references:

Side note: IF you place script blocks within markup, it may effect layout in certain browsers by taking up space (ie7 and opera 9.2 are known to have this issue) so place them in a hidden div (use a css class like: .hide { display: none; visibility: hidden; } on the div)

Standards: Note that the standards allow placement of the script blocks virtually anywhere if that is in question: http://www.w3.org/TR/1999/REC-html401-19991224/sgml/dtd.html and http://www.w3.org/TR/xhtml11/xhtml11_dtd.html

EDIT2: Note that whenever possible (always?) you should put the actual Javascript in external files and reference those - this does not change the pertinent sequence validity.

Spool Command: Do not output SQL statement to file

You can directly export the query result with export option in the result grig. This export has various options to export. I think this will work.

Display text from .txt file in batch file

A handy timestamp format:

%date:~3,2%/%date:~0,2%/%date:~6,2%-%time:~0,8%

position fixed header in html

Your #container should be outside of the #header-wrap, then specify a fixed height for #header-wrap, after, specify margin-top for #container equal to the #header-wrap's height. Something like this:

#header-wrap {
    position: fixed;
    height: 200px;
    top: 0;
    width: 100%;
    z-index: 100;
}
#container{ 
    margin-top: 200px;
}

Hope this is what you need: http://jsfiddle.net/KTgrS/

Detect if range is empty

This single line works better imho:

Application.Evaluate("SUMPRODUCT(--(E10:E14<>""""))=0")

in this case, it evaluates if range E10:E14 is empty.

How to set background image of a view?

simple way :

   -(void) viewDidLoad {
   self.view.backgroundColor = [[UIColor alloc] initWithPatternImage:[UIImage       imageNamed:@"background.png"]];
    [super viewDidLoad];
    }

How to ORDER BY a SUM() in MySQL?

This is how you do it

SELECT ID,NAME, (C_COUNTS+F_COUNTS) AS SUM_COUNTS 
FROM TABLE 
ORDER BY SUM_COUNTS LIMIT 20

The SUM function will add up all rows, so the order by clause is useless, instead you will have to use the group by clause.

How do I use Apache tomcat 7 built in Host Manager gui?

Well if you are using Netbeans in Linux, then you should look for the tomcat-user.xml in

/home/Username/.netbeans/8.0/apache-tomcat-8.0.3.0_base/conf (its called Catalina Base and is often hidden)

instead of the apacahe installation directory.

open tomcat-user.xml inside that folder, uncomment the user and roles and add/replace the following line.

    <user username="tomcat" password="tomcat" roles="tomcat,admin,admin-gui,manager,manager-gui"/>

restart the server . That's all

How to configure Visual Studio to use Beyond Compare

In Visual Studio 2008 + , go to the

Tools menu -->  select Options 

enter image description here

In Options Window --> expand Source Control --> Select Subversion User Tools --> Select Beyond Compare

and click OK button..

Which websocket library to use with Node.js?

Update: This answer is outdated as newer versions of libraries mentioned are released since then.

Socket.IO v0.9 is outdated and a bit buggy, and Engine.IO is the interim successor. Socket.IO v1.0 (which will be released soon) will use Engine.IO and be much better than v0.9. I'd recommend you to use Engine.IO until Socket.IO v1.0 is released.

"ws" does not support fallback, so if the client browser does not support websockets, it won't work, unlike Socket.IO and Engine.IO which uses long-polling etc if websockets are not available. However, "ws" seems like the fastest library at the moment.

See my article comparing Socket.IO, Engine.IO and Primus: https://medium.com/p/b63bfca0539

Passing an array by reference

The following creates a generic function, taking an array of any size and of any type by reference:

template<typename T, std::size_t S>
void my_func(T (&arr)[S]) {
   // do stuff
}

play with the code.

Error after upgrading pip: cannot import name 'main'

You can resolve this issue by reinstalling pip.

Use one of the following command line commands to reinstall pip:

Python2:

python -m pip uninstall pip && sudo apt install python-pip --reinstall

Python3:

 python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall

How to get all keys with their values in redis

KEYS command should not be used on Redis production instances if you have a lot of keys, since it may block the Redis event loop for several seconds.

I would generate a dump (bgsave), and then use the following Python package to parse it and extract the data:

https://github.com/sripathikrishnan/redis-rdb-tools

You can have json output, or customize your own output in Python.

Parse rfc3339 date strings in Python?

You should have a look at moment which is a python port of the excellent js lib momentjs.

One advantage of it is the support of ISO 8601 strings formats, as well as a generic "% format" :

import moment
time_string='2012-10-09T19:00:55Z'

m = moment.date(time_string, '%Y-%m-%dT%H:%M:%SZ')
print m.format('YYYY-M-D H:M')
print m.weekday

Result:

2012-10-09 19:10
2

Powershell script to see currently logged in users (domain and machine) + status (active, idle, away)

Here is my Approach based on DarKalimHero's Suggestion by selecting only on Explorer.exe processes

Function Get-RdpSessions 
{
    param(
        [string]$computername 
    )

    $processinfo = Get-WmiObject -Query "select * from win32_process where name='explorer.exe'" -ComputerName $computername

    $processinfo | ForEach-Object { $_.GetOwner().User } | Sort-Object -Unique | ForEach-Object { New-Object psobject -Property @{Computer=$computername;LoggedOn=$_} } | Select-Object Computer,LoggedOn
}

What's the CMake syntax to set and use variables?

When writing CMake scripts there is a lot you need to know about the syntax and how to use variables in CMake.

The Syntax

Strings using set():

  • set(MyString "Some Text")
  • set(MyStringWithVar "Some other Text: ${MyString}")
  • set(MyStringWithQuot "Some quote: \"${MyStringWithVar}\"")

Or with string():

  • string(APPEND MyStringWithContent " ${MyString}")

Lists using set():

  • set(MyList "a" "b" "c")
  • set(MyList ${MyList} "d")

Or better with list():

  • list(APPEND MyList "a" "b" "c")
  • list(APPEND MyList "d")

Lists of File Names:

  • set(MySourcesList "File.name" "File with Space.name")
  • list(APPEND MySourcesList "File.name" "File with Space.name")
  • add_excutable(MyExeTarget ${MySourcesList})

The Documentation

The Scope or "What value does my variable have?"

First there are the "Normal Variables" and things you need to know about their scope:

  • Normal variables are visible to the CMakeLists.txt they are set in and everything called from there (add_subdirectory(), include(), macro() and function()).
  • The add_subdirectory() and function() commands are special, because they open-up their own scope.
    • Meaning variables set(...) there are only visible there and they make a copy of all normal variables of the scope level they are called from (called parent scope).
    • So if you are in a sub-directory or a function you can modify an already existing variable in the parent scope with set(... PARENT_SCOPE)
    • You can make use of this e.g. in functions by passing the variable name as a function parameter. An example would be function(xyz _resultVar) is setting set(${_resultVar} 1 PARENT_SCOPE)
  • On the other hand everything you set in include() or macro() scripts will modify variables directly in the scope of where they are called from.

Second there is the "Global Variables Cache". Things you need to know about the Cache:

  • If no normal variable with the given name is defined in the current scope, CMake will look for a matching Cache entry.
  • Cache values are stored in the CMakeCache.txt file in your binary output directory.
  • The values in the Cache can be modified in CMake's GUI application before they are generated. Therefore they - in comparison to normal variables - have a type and a docstring. I normally don't use the GUI so I use set(... CACHE INTERNAL "") to set my global and persistant values.

    Please note that the INTERNAL cache variable type does imply FORCE

  • In a CMake script you can only change existing Cache entries if you use the set(... CACHE ... FORCE) syntax. This behavior is made use of e.g. by CMake itself, because it normally does not force Cache entries itself and therefore you can pre-define it with another value.

  • You can use the command line to set entries in the Cache with the syntax cmake -D var:type=value, just cmake -D var=value or with cmake -C CMakeInitialCache.cmake.
  • You can unset entries in the Cache with unset(... CACHE).

The Cache is global and you can set them virtually anywhere in your CMake scripts. But I would recommend you think twice about where to use Cache variables (they are global and they are persistant). I normally prefer the set_property(GLOBAL PROPERTY ...) and set_property(GLOBAL APPEND PROPERTY ...) syntax to define my own non-persistant global variables.

Variable Pitfalls and "How to debug variable changes?"

To avoid pitfalls you should know the following about variables:

  • Local variables do hide cached variables if both have the same name
  • The find_... commands - if successful - do write their results as cached variables "so that no call will search again"
  • Lists in CMake are just strings with semicolons delimiters and therefore the quotation-marks are important
    • set(MyVar a b c) is "a;b;c" and set(MyVar "a b c") is "a b c"
    • The recommendation is that you always use quotation marks with the one exception when you want to give a list as list
    • Generally prefer the list() command for handling lists
  • The whole scope issue described above. Especially it's recommended to use functions() instead of macros() because you don't want your local variables to show up in the parent scope.
  • A lot of variables used by CMake are set with the project() and enable_language() calls. So it could get important to set some variables before those commands are used.
  • Environment variables may differ from where CMake generated the make environment and when the the make files are put to use.
    • A change in an environment variable does not re-trigger the generation process.
    • Especially a generated IDE environment may differ from your command line, so it's recommended to transfer your environment variables into something that is cached.

Sometimes only debugging variables helps. The following may help you:

  • Simply use old printf debugging style by using the message() command. There also some ready to use modules shipped with CMake itself: CMakePrintHelpers.cmake, CMakePrintSystemInformation.cmake
  • Look into CMakeCache.txt file in your binary output directory. This file is even generated if the actual generation of your make environment fails.
  • Use variable_watch() to see where your variables are read/written/removed.
  • Look into the directory properties CACHE_VARIABLES and VARIABLES
  • Call cmake --trace ... to see the CMake's complete parsing process. That's sort of the last reserve, because it generates a lot of output.

Special Syntax

  • Environment Variables
    • You can can read $ENV{...} and write set(ENV{...} ...) environment variables
  • Generator Expressions
    • Generator expressions $<...> are only evaluated when CMake's generator writes the make environment (it comparison to normal variables that are replaced "in-place" by the parser)
    • Very handy e.g. in compiler/linker command lines and in multi-configuration environments
  • References
    • With ${${...}} you can give variable names in a variable and reference its content.
    • Often used when giving a variable name as function/macro parameter.
  • Constant Values (see if() command)
    • With if(MyVariable) you can directly check a variable for true/false (no need here for the enclosing ${...})
    • True if the constant is 1, ON, YES, TRUE, Y, or a non-zero number.
    • False if the constant is 0, OFF, NO, FALSE, N, IGNORE, NOTFOUND, the empty string, or ends in the suffix -NOTFOUND.
    • This syntax is often use for something like if(MSVC), but it can be confusing for someone who does not know this syntax shortcut.
  • Recursive substitutions
    • You can construct variable names using variables. After CMake has substituted the variables, it will check again if the result is a variable itself. This is very powerful feature used in CMake itself e.g. as sort of a template set(CMAKE_${lang}_COMPILER ...)
    • But be aware this can give you a headache in if() commands. Here is an example where CMAKE_CXX_COMPILER_ID is "MSVC" and MSVC is "1":
      • if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") is true, because it evaluates to if("1" STREQUAL "1")
      • if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC") is false, because it evaluates to if("MSVC" STREQUAL "1")
      • So the best solution here would be - see above - to directly check for if(MSVC)
    • The good news is that this was fixed in CMake 3.1 with the introduction of policy CMP0054. I would recommend to always set cmake_policy(SET CMP0054 NEW) to "only interpret if() arguments as variables or keywords when unquoted."
  • The option() command
    • Mainly just cached strings that only can be ON or OFF and they allow some special handling like e.g. dependencies
    • But be aware, don't mistake the option with the set command. The value given to option is really only the "initial value" (transferred once to the cache during the first configuration step) and is afterwards meant to be changed by the user through CMake's GUI.

References

How to deselect all selected rows in a DataGridView control?

Set

dgv.CurrentCell = null;

when user clicks on a blank part of the dgv.

How to convert a Scikit-learn dataset to a Pandas dataset?

You can use pd.DataFrame constructor, giving a numpy array (data) and a list of the names of the columns (columns). To have everything in one DataFrame, you can concatenate the features and the target into one numpy array with np.c_[...] (note the square brackets and not parenthesis). Also, you can have some trouble if you don't convert the feature names (iris['feature_names']) to a list before concatenation:

import numpy as np
import pandas as pd
from sklearn.datasets import load_iris

iris = load_iris()

df = pd.DataFrame(data= np.c_[iris['data'], iris['target']],
                     columns= list(iris['feature_names']) + ['target'])

String contains - ignore case

An optimized Imran Tariq's version

Pattern.compile(strptrn, Pattern.CASE_INSENSITIVE + Pattern.LITERAL).matcher(str1).find();

Pattern.quote(strptrn) always returns "\Q" + s + "\E" even if there is nothing to quote, concatination spoils performance.

WebAPI to Return XML

In my project with netcore 2.2 I use this code:

[HttpGet]
[Route( "something" )]
public IActionResult GetSomething()
{
    string payload = "Something";

    OkObjectResult result = Ok( payload );

    // currently result.Formatters is empty but we'd like to ensure it will be so in the future
    result.Formatters.Clear();

    // force response as xml
    result.Formatters.Add( new Microsoft.AspNetCore.Mvc.Formatters.XmlSerializerOutputFormatter() );

    return result;
}

It forces only one action within a controller to return a xml without effect to other actions. Also this code doesn't contain neither HttpResponseMessage or StringContent or ObjectContent which are disposable objects and hence should be handled appropriately (it is especially a problem if you use any of code analyzers that reminds you about it).

Going further you could use a handy extension like this:

public static class ObjectResultExtensions
{
    public static T ForceResultAsXml<T>( this T result )
        where T : ObjectResult
    {
        result.Formatters.Clear();
        result.Formatters.Add( new Microsoft.AspNetCore.Mvc.Formatters.XmlSerializerOutputFormatter() );

        return result;
    }
}

And your code will become like this:

[HttpGet]
[Route( "something" )]
public IActionResult GetSomething()
{
    string payload = "Something";

    return Ok( payload ).ForceResultAsXml();
}

In addition, this solution looks like an explicit and clean way to force return as xml and it is easy to add to your existent code.

P.S. I used fully-qualified name Microsoft.AspNetCore.Mvc.Formatters.XmlSerializerOutputFormatter just to avoid ambiguity.

Error during SSL Handshake with remote server

Faced the same problem as OP:

  • Tomcat returned response when accessing directly via SOAP UI
  • Didn't load html files
  • When used Apache properties mentioned by the previous answer, web-page appeared but AngularJS couldn't get HTTP response

Tomcat SSL certificate was expired while a browser showed it as secure - Apache certificate was far from expiration. Updating Tomcat KeyStore file solved the problem.

Is there a way to create interfaces in ES6 / Node 4?

Interfaces are not part of the ES6 but classes are.

If you really need them, you should look at TypeScript which support them.

How to stop mysqld

Try:

/usr/local/mysql/bin/mysqladmin -u root -p shutdown 

Or:

sudo mysqld stop

Or:

sudo /usr/local/mysql/bin/mysqld stop

Or:

sudo mysql.server stop

If you install the Launchctl in OSX you can try:

MacPorts

sudo launchctl unload -w /Library/LaunchDaemons/org.macports.mysql.plist
sudo launchctl load -w /Library/LaunchDaemons/org.macports.mysql.plist

Note: this is persistent after reboot.

Homebrew

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

Binary installer

sudo /Library/StartupItems/MySQLCOM/MySQLCOM stop
sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
sudo /Library/StartupItems/MySQLCOM/MySQLCOM restart

I found that in: https://stackoverflow.com/a/102094/58768

Setting public class variables

class Testclass
{
  public $testvar;

  function dosomething()
  {
    echo $this->testvar;
  }
}

$Testclass = new Testclass();
$Testclass->testvar = "another value";    
$Testclass->dosomething(); ////It will print "another value"

What is the difference between new/delete and malloc/free?

new/delete is C++, malloc/free comes from good old C.

In C++, new calls an objects constructor and delete calls the destructor.

malloc and free, coming from the dark ages before OO, only allocate and free the memory, without executing any code of the object.

bundle install returns "Could not locate Gemfile"

Think more about what you are installing and navigate Gemfile folder, then try using sudo bundle install

What is the size of column of int(11) in mysql in bytes?

As others have said, the minumum/maximum values the column can store and how much storage it takes in bytes is only defined by the type, not the length.

A lot of these answers are saying that the (11) part only affects the display width which isn't exactly true, but mostly.

A definition of int(2) with no zerofill specified will:

  • still accept a value of 100
  • still display a value of 100 when output (not 0 or 00)
  • the display width will be the width of the largest value being output from the select query.

The only thing the (2) will do is if zerofill is also specified:

  • a value of 1 will be shown 01.
  • When displaying values, the column will always have a width of the maximum possible value the column could take which is 10 digits for an integer, instead of the miniumum width required to display the largest value that column needs to show for in that specific select query, which could be much smaller.
  • The column can still take, and show a value exceeding the length, but these values will not be prefixed with 0s.

The best way to see all the nuances is to run:

CREATE TABLE `mytable` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `int1` int(10) NOT NULL,
    `int2` int(3) NOT NULL,
    `zf1` int(10) ZEROFILL NOT NULL,
    `zf2` int(3) ZEROFILL NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `mytable` 
(`int1`, `int2`, `zf1`, `zf2`) 
VALUES
(10000, 10000, 10000, 10000),
(100, 100, 100, 100);

select * from mytable;

which will output:

+----+-------+-------+------------+-------+
| id | int1  | int2  | zf1        | zf2   |
+----+-------+-------+------------+-------+
|  1 | 10000 | 10000 | 0000010000 | 10000 |
|  2 |   100 |   100 | 0000000100 |   100 |
+----+-------+-------+------------+-------+

This answer is tested against MySQL 5.7.12 for Linux and may or may not vary for other implementations.

How can I center text (horizontally and vertically) inside a div block?

This works for me (tested OK!):

HTML:

<div class="mydiv">
    <p>Item to be centered!</p>
</div>

CSS:

.mydiv {
    height: 100%; /* Or other */
    position: relative;
}

.mydiv p {
    margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    margin-right: -50%;
    transform: translate(-50%, -50%); /* To compensate own width and height */
}

You can choose other values than 50%. For example, 25% to center at 25% of parent.

Accessing JSON elements

import json
weather = urllib2.urlopen('url')
wjson = weather.read()
wjdata = json.loads(wjson)
print wjdata['data']['current_condition'][0]['temp_C']

What you get from the url is a json string. And your can't parse it with index directly. You should convert it to a dict by json.loads and then you can parse it with index.

Instead of using .read() to intermediately save it to memory and then read it to json, allow json to load it directly from the file:

wjdata = json.load(urllib2.urlopen('url'))

how to open *.sdf files?

It's a SQL Compact database. You need to define what you mean by "Open". You can open it via code with the SqlCeConnection so you can write your own tool/app to access it.

Visual Studio can also open the files directly if was created with the right version of SQL Compact.

There are also some third-party tools for manipulating them.

Convert ASCII TO UTF-8 Encoding

ASCII is a subset of UTF-8, so if a document is ASCII then it is already UTF-8.

OS X Sprite Kit Game Optimal Default Window Size

You should target the smallest, not the largest, supported pixel resolution by the devices your app can run on.

Say if there's an actual Mac computer that can run OS X 10.9 and has a native screen resolution of only 1280x720 then that's the resolution you should focus on. Any higher and your game won't correctly run on this device and you could as well remove that device from your supported devices list.

You can rely on upscaling to match larger screen sizes, but you can't rely on downscaling to preserve possibly important image details such as text or smaller game objects.

The next most important step is to pick a fitting aspect ratio, be it 4:3 or 16:9 or 16:10, that ideally is the native aspect ratio on most of the supported devices. Make sure your game only scales to fit on devices with a different aspect ratio.

You could scale to fill but then you must ensure that on all devices the cropped areas will not negatively impact gameplay or the use of the app in general (ie text or buttons outside the visible screen area). This will be harder to test as you'd actually have to have one of those devices or create a custom build that crops the view accordingly.

Alternatively you can design multiple versions of your game for specific and very common screen resolutions to provide the best game experience from 13" through 27" displays. Optimized designs for iMac (desktop) and a Macbook (notebook) devices make the most sense, it'll be harder to justify making optimized versions for 13" and 15" plus 21" and 27" screens.

But of course this depends a lot on the game. For example a tile-based world game could simply provide a larger viewing area onto the world on larger screen resolutions rather than scaling the view up. Provided that this does not alter gameplay, like giving the player an unfair advantage (specifically in multiplayer).

You should provide @2x images for the Retina Macbook Pro and future Retina Macs.

How do you handle a "cannot instantiate abstract class" error in C++?

An abstract class cannot be instantiated by definition. In order to use this class, you must create a concrete subclass which implements all virtual functions of the class. In this case, you most likely have not implemented all the virtual functions declared in Light. This means that AmbientOccluder defaults to an abstract class. For us to further help you, you should include the details of the Light class.

React - How to get parameter value from query string?

As far as I know there are three methods you can do that.

1.use regular expression to get query string.

2.you can use the browser api. image the current url is like this:

http://www.google.com.au?token=123

we just want to get 123;

First

 const query = new URLSearchParams(this.props.location.search);

Then

const token = query.get('token')
console.log(token)//123

3. use a third library called 'query-string'. First install it

npm i query-string

Then import it to the current javascript file:

 import queryString from 'query-string'

Next step is to get 'token' in the current url, do the following:

const value=queryString.parse(this.props.location.search);
const token=value.token;
console.log('token',token)//123

Hope it helps.

Updated on 25/02/2019

  1. if the current url looks like the following:

http://www.google.com.au?app=home&act=article&aid=160990

we define a function to get the parameters:

function getQueryVariable(variable)
{
        var query = window.location.search.substring(1);
        console.log(query)//"app=article&act=news_content&aid=160990"
        var vars = query.split("&");
        console.log(vars) //[ 'app=article', 'act=news_content', 'aid=160990' ]
        for (var i=0;i<vars.length;i++) {
                    var pair = vars[i].split("=");
                    console.log(pair)//[ 'app', 'article' ][ 'act', 'news_content' ][ 'aid', '160990' ] 
        if(pair[0] == variable){return pair[1];}
         }
         return(false);
}

We can get 'aid' by :

getQueryVariable('aid') //160990

Building and running app via Gradle and Android Studio is slower than via Eclipse

Solved mine with

File -> Settings -> Build, Execution, Deployment -> Build Tools -> Gradle -> Offline work

Gradle builds went from 8 minutes to 3 seconds.

FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197)

In my project I had the same error, I restarted Tomcat and it worked, withtout killing the java process.

How to get the MD5 hash of a file in C++?

Here's a straight forward implementation of the md5sum command that computes and displays the MD5 of the file specified on the command-line. It needs to be linked against the OpenSSL library (gcc md5.c -o md5 -lssl) to work. It's pure C, but you should be able to adapt it to your C++ application easily enough.

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/md5.h>

unsigned char result[MD5_DIGEST_LENGTH];

// Print the MD5 sum as hex-digits.
void print_md5_sum(unsigned char* md) {
    int i;
    for(i=0; i <MD5_DIGEST_LENGTH; i++) {
            printf("%02x",md[i]);
    }
}

// Get the size of the file by its file descriptor
unsigned long get_size_by_fd(int fd) {
    struct stat statbuf;
    if(fstat(fd, &statbuf) < 0) exit(-1);
    return statbuf.st_size;
}

int main(int argc, char *argv[]) {
    int file_descript;
    unsigned long file_size;
    char* file_buffer;

    if(argc != 2) { 
            printf("Must specify the file\n");
            exit(-1);
    }
    printf("using file:\t%s\n", argv[1]);

    file_descript = open(argv[1], O_RDONLY);
    if(file_descript < 0) exit(-1);

    file_size = get_size_by_fd(file_descript);
    printf("file size:\t%lu\n", file_size);

    file_buffer = mmap(0, file_size, PROT_READ, MAP_SHARED, file_descript, 0);
    MD5((unsigned char*) file_buffer, file_size, result);
    munmap(file_buffer, file_size); 

    print_md5_sum(result);
    printf("  %s\n", argv[1]);

    return 0;
}

How to SSH into Docker?

I guess it is possible. You just need to install a SSH server in each container and expose a port on the host. The main annoyance would be maintaining/remembering the mapping of port to container.

However, I have to question why you'd want to do this. SSH'ng into containers should be rare enough that it's not a hassle to ssh to the host then use docker exec to get into the container.

Global variables in Javascript across multiple files

I think you should be using "local storage" rather than global variables.

If you are concerned that "local storage" may not be supported in very old browsers, consider using an existing plug-in which checks the availability of "local storage" and uses other methods if it isn't available.

I used http://www.jstorage.info/ and I'm happy with it so far.

Custom li list-style with font-awesome icon

As per the Font Awesome Documentation:

<ul class="fa-ul">
  <li><i class="fa-li fa fa-check"></i>Barbabella</li>
  <li><i class="fa-li fa fa-check"></i>Barbaletta</li>
  <li><i class="fa-li fa fa-check"></i>Barbalala</li>
</ul>

Or, using Jade:

ul.fa-ul
  li
    i.fa-li.fa.fa-check
    | Barbabella
  li
    i.fa-li.fa.fa-check
    | Barbaletta
  li
    i.fa-li.fa.fa-check
    | Barbalala

Linking dll in Visual Studio

Assume that the source file you want to compile is main.cpp and your example_dll.dll and example_dll.lib . now run cl.exe main.cpp /EHsc /link example_dll.lib now you may get main.exe

Format numbers to strings in Python

You can use the str.format() to make Python recognize any objects to strings.

Conversion from Long to Double in Java

You could simply do :

double d = (double)15552451L;

Or you could get double from Long object as :

Long l = new Long(15552451L);
double d = l.doubleValue();

Tool for sending multipart/form-data request

The usual error is one tries to put Content-Type: {multipart/form-data} into the header of the post request. That will fail, it is best to let Postman do it for you. For example:

Suggestion To Load Via Postman Body Part

Fails If In Header Common Error

Works should remove content type from the Header

Detecting endianness programmatically in a C++ program

I was going through the textbook:Computer System: a programmer's perspective, and there is a problem to determine which endian is this by C program.

I used the feature of the pointer to do that as following:

#include <stdio.h>

int main(void){
    int i=1;
    unsigned char* ii = &i;

    printf("This computer is %s endian.\n", ((ii[0]==1) ? "little" : "big"));
    return 0;
}

As the int takes up 4 bytes, and char takes up only 1 bytes. We could use a char pointer to point to the int with value 1. Thus if the computer is little endian, the char that char pointer points to is with value 1, otherwise, its value should be 0.

How do you display JavaScript datetime in 12 hour AM/PM format?

Here is another way that is simple, and very effective:

        var d = new Date();

        var weekday = new Array(7);
        weekday[0] = "Sunday";
        weekday[1] = "Monday";
        weekday[2] = "Tuesday";
        weekday[3] = "Wednesday";
        weekday[4] = "Thursday";
        weekday[5] = "Friday";
        weekday[6] = "Saturday";

        var month = new Array(11);
        month[0] = "January";
        month[1] = "February";
        month[2] = "March";
        month[3] = "April";
        month[4] = "May";
        month[5] = "June";
        month[6] = "July";
        month[7] = "August";
        month[8] = "September";
        month[9] = "October";
        month[10] = "November";
        month[11] = "December";

        var t = d.toLocaleTimeString().replace(/:\d+ /, ' ');

        document.write(weekday[d.getDay()] + ',' + " " + month[d.getMonth()] + " " + d.getDate() + ',' + " " + d.getFullYear() + '<br>' + d.toLocaleTimeString());

    </script></div><!-- #time -->

How to set the authorization header using curl

For HTTP Basic Auth:

curl -H "Authorization: Basic <_your_token_>" http://www.example.com

replace _your_token_ and the URL.

phpMyAdmin on MySQL 8.0

I had this problem, did not find any ini file in Windows, but the solution that worked for me was very simple.
1. Open the mysql installer.
2. Reconfigure mysql server, it is the first link.
3. Go to authentication method.
4. Choose 'Legacy authentication'.
5. Give your password(next field).
6. Apply changes.

That's it, hope my solution works fine for you as well!

auto create database in Entity Framework Core

If you haven't created migrations, there are 2 options

1.create the database and tables from application Main:

var context = services.GetRequiredService<YourRepository>();
context.Database.EnsureCreated();

2.create the tables if the database already exists:

var context = services.GetRequiredService<YourRepository>();
context.Database.EnsureCreated();
RelationalDatabaseCreator databaseCreator =
(RelationalDatabaseCreator)context.Database.GetService<IDatabaseCreator>();
databaseCreator.CreateTables();

Thanks to Bubi's answer

Running python script inside ipython

The %run magic has a parameter file_finder that it uses to get the full path to the file to execute (see here); as you note, it just looks in the current directory, appending ".py" if necessary.

There doesn't seem to be a way to specify which file finder to use from the %run magic, but there's nothing to stop you from defining your own magic command that calls into %run with an appropriate file finder.

As a very nasty hack, you could override the default file_finder with your own:

IPython.core.magics.execution.ExecutionMagics.run.im_func.func_defaults[2] = my_file_finder

To be honest, at the rate the IPython API is changing that's as likely to continue to work as defining your own magic is.

Should I set max pool size in database connection string? What happens if I don't?

We can define maximum pool size in following way:

                <pool> 
               <min-pool-size>5</min-pool-size>
                <max-pool-size>200</max-pool-size>
                <prefill>true</prefill>
                <use-strict-min>true</use-strict-min>
                <flush-strategy>IdleConnections</flush-strategy>
                </pool>

curl: (6) Could not resolve host: application

I replaced all the single quotes ['] to double quotes ["] and then it worked perfectly. Thanks for the input by @LogicalKip.

What is the proper way to re-attach detached objects in Hibernate?

I went back to the JavaDoc for org.hibernate.Session and found the following:

Transient instances may be made persistent by calling save(), persist() or saveOrUpdate(). Persistent instances may be made transient by calling delete(). Any instance returned by a get() or load() method is persistent. Detached instances may be made persistent by calling update(), saveOrUpdate(), lock() or replicate(). The state of a transient or detached instance may also be made persistent as a new persistent instance by calling merge().

Thus update(), saveOrUpdate(), lock(), replicate() and merge() are the candidate options.

update(): Will throw an exception if there is a persistent instance with the same identifier.

saveOrUpdate(): Either save or update

lock(): Deprecated

replicate(): Persist the state of the given detached instance, reusing the current identifier value.

merge(): Returns a persistent object with the same identifier. The given instance does not become associated with the session.

Hence, lock() should not be used straightway and based on the functional requirement one or more of them can be chosen.

How to solve time out in phpmyadmin?

I'm using version 4.0.3 of MAMP along with phpmyadmin. The top of /Applications/MAMP/bin/phpMyAdmin/libraries/config.default.php reads:

DO NOT EDIT THIS FILE, EDIT config.inc.php INSTEAD !!!

Changing the following line in /Applications/MAMP/bin/phpMyAdmin/config.inc.php and restarting MAMP worked for me.

$cfg['ExecTimeLimit'] = 0;

rename the columns name after cbind the data

If you offer cbind a set of arguments all of whom are vectors, you will get not a dataframe, but rather a matrix, in this case an all character matrix. They have different features. You can get a dataframe if some of your arguments remain dataframes, Try:

merger <- cbind(Date =as.character(Date),
             weather1[ , c("High", "Low", "Avg..High", "Avg.Low")] , 
             ScnMov =sale$Scanned.Movement[a] )

Load a Bootstrap popover content with AJAX. Is this possible?

Here is my solution which works fine with ajax loaded content too.

/*
 * popover handler assigned document (or 'body') 
 * triggered on hover, show content from data-content or 
 * ajax loaded from url by using data-remotecontent attribute
 */
$(document).popover({
    selector: 'a.preview',
    placement: get_popover_placement,
    content: get_popover_content,
    html: true,
    trigger: 'hover'
});

function get_popover_content() {
    if ($(this).attr('data-remotecontent')) {
        // using remote content, url in $(this).attr('data-remotecontent')
        $(this).addClass("loading");
        var content = $.ajax({
            url: $(this).attr('data-remotecontent'),
            type: "GET",
            data: $(this).serialize(),
            dataType: "html",
            async: false,
            success: function() {
                // just get the response
            },
            error: function() {
                // nothing
            }
        }).responseText;
        var container = $(this).attr('data-rel');
        $(this).removeClass("loading");
        if (typeof container !== 'undefined') {
            // show a specific element such as "#mydetails"
            return $(content).find(container);
        }
        // show the whole page
        return content;
    }
    // show standard popover content
    return $(this).attr('data-content');
}

function get_popover_placement(pop, el) {
    if ($(el).attr('data-placement')) {
        return $(el).attr('data-placement');
    }
    // find out the best placement
    // ... cut ...
    return 'left';
}

C# Debug - cannot start debugging because the debug target is missing

Please try with the steps below:

  1. Right click on the Visual Studio Project - Properties - Debug - (Start Action section) - select "Start project" radio button.
  2. Right click on the Visual Studio Project - Properties - Debug - (Enable Debuggers section) - mark "Enable the Visual Studio hosting process"
  3. Save changes Ctrl + Shift + S) and run the project again.

P.S. I experienced the same problem when I was playing with the options to redirect the console input / output to text file and have selected the option Properties - Debug - (Start Action section) - Start external program. When I moved the Solution to another location on my computer the problem occurred because it was searching for an absolute path to the executable file. Restoring the Visual Studio Project default settings (see above) fixed the problem. For your reference I am using Visual Studio 2013 Professional.

How can I git stash a specific file?

To add to svick's answer, the -m option simply adds a message to your stash, and is entirely optional. Thus, the command

git stash push [paths you wish to stash]

is perfectly valid. So for instance, if I want to only stash changes in the src/ directory, I can just run

git stash push src/

How to use gitignore command in git

So based on what you said, these files are libraries/documentation you don't want to delete but also don't want to push to github. Let say you have your project in folder your_project and a doc directory: your_project/doc.

  1. Remove it from the project directory (without actually deleting it): git rm --cached doc/*
  2. If you don't already have a .gitignore, you can make one right inside of your project folder: project/.gitignore.
  3. Put doc/* in the .gitignore
  4. Stage the file to commit: git add project/.gitignore
  5. Commit: git commit -m "message".
  6. Push your change to github.

Select from table by knowing only date without time (ORACLE)

DATE is a reserved keyword in Oracle, so I'm using column-name your_date instead.

If you have an index on your_date, I would use

WHERE your_date >= TO_DATE('2010-08-03', 'YYYY-MM-DD')
  AND your_date <  TO_DATE('2010-08-04', 'YYYY-MM-DD')

or BETWEEN:

WHERE your_date BETWEEN TO_DATE('2010-08-03', 'YYYY-MM-DD')
                    AND TO_DATE('2010-08-03 23:59:59', 'YYYY-MM-DD HH24:MI:SS')

If there is no index or if there are not too many records

WHERE TRUNC(your_date) = TO_DATE('2010-08-03', 'YYYY-MM-DD')

should be sufficient. TRUNC without parameter removes hours, minutes and seconds from a DATE.


If performance really matters, consider putting a Function Based Index on that column:

CREATE INDEX trunc_date_idx ON t1(TRUNC(your_date));

ASP.NET DateTime Picker

If you would like to work with a textbox, be aware that setting the TextMode property to "Date" will not work on Internet Explorer 11, because it does not currently support the "Date", "DateTime", nor "Time" values.

This example illustrates how to implement it using a textbox, including validation of the dates (since the user could enter just numbers). It will work on Internet Explorer 11 as well other web browsers.

<asp:Content ID="Content"
         ContentPlaceHolderID="MainContent"
         runat="server">

<link rel="stylesheet"
    href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css" />
   <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
   <script>
   $(function () {
   $("#
   <%= txtBoxDate.ClientID %>").datepicker();
   });
 </script>
 <asp:TextBox ID="txtBoxDate"
           runat="server"
           Width="135px"
           AutoPostBack="False"
           TabIndex="1"
           placeholder="mm/dd/yyyy"
           autocomplete="off"
           MaxLength="10"></asp:TextBox>
 <asp:CompareValidator ID="CompareValidator1"
                    runat="server"
                    ControlToValidate="txtBoxDate"
                    Operator="DataTypeCheck"
                    Type="Date">Date invalid, please check format. 
 </asp:CompareValidator>
 </asp:Content>

What is the point of the diamond operator (<>) in Java 7?

This line causes the [unchecked] warning:

List<String> list = new LinkedList();

So, the question transforms: why [unchecked] warning is not suppressed automatically only for the case when new collection is created?

I think, it would be much more difficult task then adding <> feature.

UPD: I also think that there would be a mess if it were legally to use raw types 'just for a few things'.

How do I POST JSON data with cURL?

You can pass the extension of the format you want as the end of the url. like http://localhost:8080/xx/xxx/xxxx.json

or

http://localhost:8080/xx/xxx/xxxx.xml

Note: you need to add jackson and jaxb maven dependencies in your pom.

Is <div style="width: ;height: ;background: "> CSS?

For example :

_x000D_
_x000D_
<div style="height:100px; width:100px; background:#000000"></div>
_x000D_
_x000D_
_x000D_

here.

you give css to div of height and width having 100px and background as black.

PS : try to avoid inline-css you can make external CSS and import in your html file.

you can refer here for CSS

hope this helps.

How can I schedule a job to run a SQL query daily?

if You want daily backup // following sql script store in C:\Users\admin\Desktop\DBScript\DBBackUpSQL.sql

DECLARE @pathName NVARCHAR(512),
 @databaseName NVARCHAR(512) SET @databaseName = 'Databasename' SET @pathName = 'C:\DBBackup\DBData\DBBackUp' + Convert(varchar(8), GETDATE(), 112) + '_' + Replace((Convert(varchar(8), GETDATE(), 108)),':','-')+ '.bak' BACKUP DATABASE @databaseName TO DISK = @pathName WITH NOFORMAT, 
INIT, 
NAME = N'', 
SKIP, 
NOREWIND, 
NOUNLOAD, 
STATS = 10 
GO

open the Task scheduler

create task-> select Triggers tab Select New .

Button Select Daily Radio button

click Ok Button

then click Action tab Select New.

Button Put "C:\Program Files\Microsoft SQL Server\100\Tools\Binn\SQLCMD.EXE" -S ADMIN-PC -i "C:\Users\admin\Desktop\DBScript\DBBackUpSQL.sql" in the program/script text box(make sure Match your files path and Put the double quoted path in start-> search box and if it find then click it and see the backup is there or not)

-- the above path may be insted 100 write 90 "C:\Program Files\Microsoft SQL Server\90\Tools\Binn\SQLCMD.EXE" -S ADMIN-PC -i "C:\Users\admin\Desktop\DBScript\DBBackUpSQL.sql"

then click ok button

the Script will execute on time which you select on Trigger tab on daily basis

enjoy it.............

How can I add a new column and data to a datatable that already contains data?

Should it not be foreach instead of for!?

//call SQL helper class to get initial data  
DataTable dt = sql.ExecuteDataTable("sp_MyProc"); 

dt.Columns.Add("MyRow", **typeof**(System.Int32)); 

foreach(DataRow dr in dt.Rows) 
{ 
    //need to set value to MyRow column 
    dr["MyRow"] = 0;   // or set it to some other value 
} 

How to download HTTP directory with all files and sub-directories as they appear on the online files/folders list?

I was able to get this to work thanks to this post utilizing VisualWGet. It worked great for me. The important part seems to be to check the -recursive flag (see image).

Also found that the -no-parent flag is important, othewise it will try to download everything.

enter image description here enter image description here

How to do joins in LINQ on multiple fields in single join

I think a more readable and flexible option is to use Where function:

var result = from x in entity1
             from y in entity2
                 .Where(y => y.field1 == x.field1 && y.field2 == x.field2)

This also allows to easily change from inner join to left join by appending .DefaultIfEmpty().

C# How to determine if a number is a multiple of another?

followings programs will execute,"one number is multiple of another" in

#include<stdio.h>
int main
{
int a,b;
printf("enter any two number\n");
scanf("%d%d",&a,&b);
if (a%b==0)
printf("this is  multiple number");
else if (b%a==0);
printf("this is multiple number");
else
printf("this is not multiple number");
return 0;
}

nginx- duplicate default server error

You likely have other files (such as the default configuration) located in /etc/nginx/sites-enabled that needs to be removed.

This issue is caused by a repeat of the default_server parameter supplied to one or more listen directives in your files. You'll likely find this conflicting directive reads something similar to:

listen 80 default_server;

As the nginx core module documentation for listen states:

The default_server parameter, if present, will cause the server to become the default server for the specified address:port pair. If none of the directives have the default_server parameter then the first server with the address:port pair will be the default server for this pair.

This means that there must be another file or server block defined in your configuration with default_server set for port 80. nginx is encountering that first before your mysite.com file so try removing or adjusting that other configuration.

If you are struggling to find where these directives and parameters are set, try a search like so:

grep -R default_server /etc/nginx

Difference between break and continue statement

Consider the following:

int n;
for(n = 0; n < 10; ++n) {
    break;
}
System.out.println(n);

break causes the loop to terminate and the value of n is 0.

int n;
for(n = 0; n < 10; ++n) {
    continue;
}
System.out.println(n);

continue causes the program counter to return to the first line of the loop (the condition is checked and the value of n is increment) and the final value of n is 10.

It should also be noted that break only terminates the execution of the loop it is within:

int m;
for(m = 0; m < 5; ++m)
{
    int n;
    for(n = 0; n < 5; ++n) {
        break;
    }
    System.out.println(n);
}
System.out.println(m);

Will output something to the effect of

0
0
0
0
0
5

Can't start hostednetwork

I encountered this problem on my laptop. I found the solution for this problem.

  1. Test this command in the command prompt "netsh wlan show driver".
  2. See Hosted network supported.
  3. If it is no,

Then do this

  1. Go to device manager.
  2. Click on view and press on "show hidden devices".
  3. Go down to the list of devices and expand the node "Network Devices" .
  4. Find an adapter with the name "Microsoft Hosted Network Virtual Adapter" and then right click on it.
  5. Select Enable
  6. This will enable the AdHoc created connection, it should appear in the network connections in Network and Sharing Center, if the AdHoc network connection is not appear then open elevated command prompt and apply this command "netsh wlan stop hostednetwork" without quotations.
  7. After this, the connection should appear. Then try starting your connection. It should work fine.

What is the bower (and npm) version syntax?

If there is no patch number, ~ is equivalent to appending .x to the non-tilde version. If there is a patch number, ~ allows all patch numbers >= the specified one.

~1     := 1.x
~1.2   := 1.2.x
~1.2.3 := (>=1.2.3 <1.3.0)

I don't have enough points to comment on the accepted answer, but some of the tilde information is at odds with the linked semver documentation: "angular": "~1.2" will not match 1.3, 1.4, 1.4.9. Also "angular": "~1" and "angular": "~1.0" are not equivalent. This can be verified with the npm semver calculator.

ES6 class variable alternatives

ES7 class member syntax:

ES7 has a solution for 'junking' your constructor function. Here is an example:

_x000D_
_x000D_
class Car {_x000D_
  _x000D_
  wheels = 4;_x000D_
  weight = 100;_x000D_
_x000D_
}_x000D_
_x000D_
const car = new Car();_x000D_
console.log(car.wheels, car.weight);
_x000D_
_x000D_
_x000D_

The above example would look the following in ES6:

_x000D_
_x000D_
class Car {_x000D_
_x000D_
  constructor() {_x000D_
    this.wheels = 4;_x000D_
    this.weight = 100;_x000D_
  }_x000D_
_x000D_
}_x000D_
_x000D_
const car = new Car();_x000D_
console.log(car.wheels, car.weight);
_x000D_
_x000D_
_x000D_

Be aware when using this that this syntax might not be supported by all browsers and might have to be transpiled an earlier version of JS.

Bonus: an object factory:

_x000D_
_x000D_
function generateCar(wheels, weight) {_x000D_
_x000D_
  class Car {_x000D_
_x000D_
    constructor() {}_x000D_
_x000D_
    wheels = wheels;_x000D_
    weight = weight;_x000D_
_x000D_
  }_x000D_
_x000D_
  return new Car();_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
const car1 = generateCar(4, 50);_x000D_
const car2 = generateCar(6, 100);_x000D_
_x000D_
console.log(car1.wheels, car1.weight);_x000D_
console.log(car2.wheels, car2.weight);
_x000D_
_x000D_
_x000D_

Background color of text in SVG

The solution I have used is:

_x000D_
_x000D_
<svg>
  <line x1="100" y1="100" x2="500" y2="100" style="stroke:black; stroke-width: 2"/>    
  <text x="150" y="105" style="stroke:white; stroke-width:0.6em">Hello World!</text>
  <text x="150" y="105" style="fill:black">Hello World!</text>  
</svg>
_x000D_
_x000D_
_x000D_

A duplicate text item is being placed, with stroke and stroke-width attributes. The stroke should match the background colour, and the stroke-width should be just big enough to create a "splodge" on which to write the actual text.

A bit of a hack and there are potential issues, but works for me!

How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?

You could put a _ViewStart.cshtml file inside the /Views/Public folder which would override the default one in the /Views folder and specify the desired layout:

@{
    Layout = "~/Views/Shared/_PublicLayout.cshtml";
}

By analogy you could put another _ViewStart.cshtml file inside the /Views/Staff folder with:

@{
    Layout = "~/Views/Shared/_StaffLayout.cshtml";
}

You could also specify which layout should be used when returning a view inside a controller action but that's per action:

return View("Index", "~/Views/Shared/_StaffLayout.cshtml", someViewModel);

Yet another possibility is a custom action filter which would override the layout. As you can see many possibilities to achieve this. Up to you to choose which one fits best in your scenario.


UPDATE:

As requested in the comments section here's an example of an action filter which would choose a master page:

public class LayoutInjecterAttribute : ActionFilterAttribute
{
    private readonly string _masterName;
    public LayoutInjecterAttribute(string masterName)
    {
        _masterName = masterName;
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        base.OnActionExecuted(filterContext);
        var result = filterContext.Result as ViewResult;
        if (result != null)
        {
            result.MasterName = _masterName;
        }
    }
}

and then decorate a controller or an action with this custom attribute specifying the layout you want:

[LayoutInjecter("_PublicLayout")]
public ActionResult Index()
{
    return View();
}

How to "scan" a website (or page) for info, and bring it into my program?

Use a HTML parser like Jsoup. This has my preference above the other HTML parsers available in Java since it supports jQuery like CSS selectors. Also, its class representing a list of nodes, Elements, implements Iterable so that you can iterate over it in an enhanced for loop (so there's no need to hassle with verbose Node and NodeList like classes in the average Java DOM parser).

Here's a basic kickoff example (just put the latest Jsoup JAR file in classpath):

package com.stackoverflow.q2835505;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class Test {

    public static void main(String[] args) throws Exception {
        String url = "https://stackoverflow.com/questions/2835505";
        Document document = Jsoup.connect(url).get();

        String question = document.select("#question .post-text").text();
        System.out.println("Question: " + question);

        Elements answerers = document.select("#answers .user-details a");
        for (Element answerer : answerers) {
            System.out.println("Answerer: " + answerer.text());
        }
    }

}

As you might have guessed, this prints your own question and the names of all answerers.

Error 405 (Method Not Allowed) Laravel 5

Your routes.php file needs to be setup correctly.

What I am assuming your current setup is like:

Route::post('/empresas/eliminar/{id}','CompanyController@companiesDelete');

or something. Define a route for the delete method instead.

Route::delete('/empresas/eliminar/{id}','CompanyController@companiesDelete');

Now if you are using a Route resource, the default route name to be used for the 'DELETE' method is .destroy. Define your delete logic in that function instead.

How do I clone a generic List in Java?

I think this should do the trick using the Collections API:

Note: the copy method runs in linear time.

//assume oldList exists and has data in it.
List<String> newList = new ArrayList<String>();
Collections.copy(newList, oldList);

Status bar and navigation bar appear over my view's bounds in iOS 7

You don't have to calculate how far to shift everything down, there's a build in property for this. In Interface Builder, highlight your view controller, and then navigate to the attributes inspector. Here you'll see some check boxes next to the words "Extend Edges". As you can see, in the first screenshot, the default selection is for content to appear under top and bottom bars, but not under opaque bars, which is why setting the bar style to not translucent worked for you.

As you can somewhat see in the first screenshot, there are two UI elements hiding below the navigation bar. (I've enabled wireframes in IB to illustrate this) These elements, a UIButton and a UISegmentedControl both have their "y" origin set to zero, and the view controller is set to allow content below the top bar.

enter image description here

This second screenshot shows what happens when you deselect the "Under Top Bars" check box. As you can see, the view controllers view has been shifted down appropriately for its y origin to be right underneath the navigation bar.

enter image description here

This can also be accomplished programmatically through the usage of -[UIViewController edgesForExtendedLayout]. Here's a link to the class reference for edgeForExtendedLayout, and for UIRectEdge

[self setEdgesForExtendedLayout:UIRectEdgeNone];

$("#form1").validate is not a function

Probably the browser first downloaded the validade script and then jQuery. If the validade script be downloaded before loading jQuery you'll get an error. You can see this using a tool like firebug.

Try this:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script>
    function LoadValidade() {
        var a = false;
        try {
            var teste = $('*');
            if(teste == null)
                throw 1;
        } catch (e) { 
            a = true; 
        }

        if (a){ 
            setTimeout(LoadValidade, 300);
            return;
        }

        var validadeScript = document.createElement("script");
        validadeScript.src = "../common/jquery.validate.js";
        $('head')[0].appendChild(validadeScript);
    } 
    setTimeout(LoadValidade, 300);
</script>

Excel VBA: AutoFill Multiple Cells with Formulas

The approach you're looking for is FillDown. Another way so you don't have to kick your head off every time is to store formulas in an array of strings. Combining them gives you a powerful method of inputting formulas by the multitude. Code follows:

Sub FillDown()

    Dim strFormulas(1 To 3) As Variant

    With ThisWorkbook.Sheets("Sheet1")
        strFormulas(1) = "=SUM(A2:B2)"
        strFormulas(2) = "=PRODUCT(A2:B2)"
        strFormulas(3) = "=A2/B2"

        .Range("C2:E2").Formula = strFormulas
        .Range("C2:E11").FillDown
    End With

End Sub

Screenshots:

Result as of line: .Range("C2:E2").Formula = strFormulas:

enter image description here

Result as of line: .Range("C2:E11").FillDown:

enter image description here

Of course, you can make it dynamic by storing the last row into a variable and turning it to something like .Range("C2:E" & LRow).FillDown, much like what you did.

Hope this helps!

AngularJS HTTP post to PHP and undefined

This is the best solution (IMO) as it requires no jQuery and no JSON decode:

Source: https://wordpress.stackexchange.com/a/179373 and: https://stackoverflow.com/a/1714899/196507

Summary:

//Replacement of jQuery.param
var serialize = function(obj, prefix) {
  var str = [];
  for(var p in obj) {
    if (obj.hasOwnProperty(p)) {
      var k = prefix ? prefix + "[" + p + "]" : p, v = obj[p];
      str.push(typeof v == "object" ?
        serialize(v, k) :
        encodeURIComponent(k) + "=" + encodeURIComponent(v));
    }
  }
  return str.join("&");
};

//Your AngularJS application:
var app = angular.module('foo', []);

app.config(function ($httpProvider) {
    // send all requests payload as query string
    $httpProvider.defaults.transformRequest = function(data){
        if (data === undefined) {
            return data;
        }
        return serialize(data);
    };

    // set all post requests content type
    $httpProvider.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded; charset=UTF-8';
});

Example:

...
   var data = { id: 'some_id', name : 'some_name' };
   $http.post(my_php_url,data).success(function(data){
        // It works!
   }).error(function() {
        // :(
   });

PHP code:

<?php
    $id = $_POST["id"];
?>

Parsing JSON Array within JSON Object

line 2 should be

for (int i = 0; i < jsonMainArr.size(); i++) {  // **line 2**

For line 3, I'm having to do

    JSONObject childJSONObject = (JSONObject) new JSONParser().parse(jsonMainArr.get(i).toString());

Install Qt on Ubuntu

Install Qt

sudo apt-get install build-essential

sudo apt-get install qtcreator

sudo apt-get install qt5-default

Install documentation and examples If Qt Creator is installed thanks to the Ubuntu Sofware Center or thanks to the synaptic package manager, documentation for Qt Creator is not installed. Hitting the F1 key will show you the following message : "No documentation available". This can easily be solved by installing the Qt documentation:

sudo apt-get install qt5-doc

sudo apt-get install qt5-doc-html qtbase5-doc-html

sudo apt-get install qtbase5-examples

Restart Qt Creator to make the documentation available.

Error while loading shared libraries

Problem:

radiusd: error while loading shared libraries: libfreeradius-radius-2.1.10.so: cannot open shared object file: No such file or directory

Reason:

Actually, the libraries have been installed in a place where dynamic linker cannot find it.

Solution:

While this is not a guarantee but using the following command may help you solve the “cannot open shared object file” error:

sudo /sbin/ldconfig -v

http://www.lucidarme.me/how-install-documentation-for-qt-creator/

https://ubuntuforums.org/showthread.php?t=2199929

https://itsfoss.com/error-while-loading-shared-libraries/

ModelSim-Altera error

How to clear a chart from a canvas so that hover events cannot be triggered?

I have faced the same problem few hours ago.

The ".clear()" method actually clears the canvas, but (evidently) it leaves the object alive and reactive.

Reading carefully the official documentation, in the "Advanced usage" section, I have noticed the method ".destroy()", described as follows:

"Use this to destroy any chart instances that are created. This will clean up any references stored to the chart object within Chart.js, along with any associated event listeners attached by Chart.js."

It actually does what it claims and it has worked fine for me, I suggest you to give it a try.

Expected block end YAML error

With YAML, remember that it is all about the spaces used to define configuration through the hierarchical structures (indents). Many problems encountered whilst parsing YAML documents simply stems from extra spaces (or not enough spaces) before a key value somewhere in the given YAML file.

Display tooltip on Label's hover?

If you also have jQuery UI, you can add this:

$(document).ready(function () {
  $(document).tooltip();
});

You then need a title instead of a hidden input. RGraham already posted an answer doing this for you :P

How does numpy.newaxis work and when to use it?

You started with a one-dimensional list of numbers. Once you used numpy.newaxis, you turned it into a two-dimensional matrix, consisting of four rows of one column each.

You could then use that matrix for matrix multiplication, or involve it in the construction of a larger 4 x n matrix.

How to get GMT date in yyyy-mm-dd hh:mm:ss in PHP

You had selected the time format wrong

<?php 
date_default_timezone_set('GMT');

echo date("Y-m-d,h:m:s");
?>

Creating a singleton in Python

Maybe I missunderstand the singleton pattern but my solution is this simple and pragmatic (pythonic?). This code fullfills two goals

  1. Make the instance of Foo accessiable everywhere (global).
  2. Only one instance of Foo can exist.

This is the code.

#!/usr/bin/env python3

class Foo:
    me = None

    def __init__(self):
        if Foo.me != None:
            raise Exception('Instance of Foo still exists!')

        Foo.me = self


if __name__ == '__main__':
    Foo()
    Foo()

Output

Traceback (most recent call last):
  File "./x.py", line 15, in <module>
    Foo()
  File "./x.py", line 8, in __init__
    raise Exception('Instance of Foo still exists!')
Exception: Instance of Foo still exists!

Characters allowed in a URL

The upcoming change is for chinese, arabic domain names not URIs. The internationalised URIs are called IRIs and are defined in RFC 3987. However, having said that I'd recommend not doing this yourself but relying on an existing, tested library since there are lots of choices of URI encoding/decoding and what are considered safe by specification, versus what are safe by actual use (browsers).